University of Groningen Carbon-carbon bond formations using organolithium reagents Heijnen, Dorus

University of Groningen

Carbon-carbon bond formations using organolithium reagents

Heijnen, Dorus

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Chapter 6 : Nickel-Catalyzed Cross-Coupling of Organolithium

Reagents with (Hetero)Aryl Electrophiles

Nickel-catalyzed selective cross-coupling of aromatic electrophiles (bromides, chlorides,

fluorides and methyl ethers) with organolithium reagents is described in this chapter. The use

of a commercially available nickel N-heterocyclic carbene (NHC) complex allows the

reaction with a variety of (hetero)aryllithium compounds, including those prepared via

metal-halogen exchange or direct metallation, whereas a commercially available electron-rich

nickel-bisphosphine complex also readily converts alkyllithium species into the corresponding

coupled product. These reactions proceed rapidly (1h) under mild conditions (room

temperature) while avoiding the undesired formation of reduced or homocoupled products.

Part of this chapter was published in : D. Heijnen J. Gualtierotti, V. Hornillos, and B. L. Feringa Chem. Eur. J. 2016, 22, 3991-3995

6.1 Introduction

In the ongoing search for more efficient, environmentally benign and economically

sustainable processes, current research in cross-coupling methodologies has shown a growing

interest in the use of earth-abundant metal-based catalysts.

Although palladium is applied in

the majority of these processes, catalytic systems based on iron, nickel, or cobalt have proven

suitable alternatives in several cases. In particular, the use of nickel has witnessed a rapid

growth owing to its low cost and unique properties.

Nickel undergoes oxidative addition

more readily than palladium although reductive elimination is correspondingly more

difficult.

Ni

/Ni

catalytic cycles are well known,

but Ni

and Ni

oxidation states

can be also accessed, allowing for different modes of reactivity and for radical mechanisms to

operate.

Scheme 6.1 Previous and current nickel and organolithium catalysis

Nickel has been extensively used in cross-coupling of organoboron and organozinc reagents

with organic halides (Scheme 6.1a).

For example, a highly efficient nickel-catalyzed

method for the synthesis of heterobiaryls at low temperature described by the group of

Hartwig highlights the potential of nickel in Suzuki-Miyaura reactions.

Since the early

reports by Kumada and co-workers in 1972, Grignard reagents in combination with nickel are

known to be effective in the cross-coupling with aryl halides,

and these organometallic

reagents were also the first to be efficiently employed in reactions with the less reactive

aromatic ethers.

Various groups have further developed the use of Grignard reagents and

other nucleophiles, including organozinc and organoboron compounds, in nickel-catalyzed

cross-coupling with aryl

and benzyl ethers

(Scheme 6.1a). Additionally, nickel has also

been found to activate very strong C-F bonds.

Thus, the coupling of aromatic fluorides with

organometallic compounds has been reported, although activated fluoroarenes or

polyfluorinated aromatic substrates are usually employed.

Some of these reactions suffer

from competing isomerization of the alkyl coupling partners.

In sharp contrast, the direct use of organolithium reagents, among the most versatile and

widely used reagents in organic synthesis,

in nickel-catalyzed cross-couplings reactions has

been limited to the polymerization of lithiated (hetero)arenes,

the coupling of

(trimethylsilyl)methyllithium with aromatic ethers (Scheme 6.1b),

and the homo-coupling

of arylbromides.

Despite these important advances, a general method for the

nickel-catalyzed cross-coupling of alkyl and (hetero)aryllithium reagents with aryl(pseudo)halides

remains elusive.

Organolithium compounds

are commercially available or readily accessible by

lithium-halogen exchange and they are often employed as precursors for other organometallic

compounds (Mg, B, Zn, Sn) used in cross-coupling reactions. Their direct use drastically

reduces the amount of byproducts with the light lithium halide being the only stoichiometric

reaction waste. Our group recently described the direct use of these reagents in

palladium-catalyzed cross-coupling under mild conditions of a wide variety of organic bromides,

chlorides,

and triflates,

providing high yields and selectivities (Scheme 6.1c).

Considering the advantages associated with the use of nickel-based catalytic systems, the

development of a general nickel-catalyzed cross-coupling with easily accessible

organolithium reagents will provide a highly desirable alternative to existing methodologies.

Moreover, since the palladium-catalyzed methods with these reagents are based on the use of

aryl bromides, chlorides, and triflates, we were interested in exploring the coupling of less

reactive fluorides and aromatic ethers, the latter being obtained from a pool of starting

materials entirely distinct from aryl halides.

Herein, we report that the use of a commercially available nickel N-heterocyclic carbene

(NHC) or bisphosphine complex allows for the selective cross-coupling of organolithium

compounds with aryl bromides, chlorides, fluorides, and methyl ethers in high selectivity

under mild conditions (RT) and within short reaction times (1h; Scheme 6.1d).

6.2 Optimization and scope

In preliminary studies, we focused on reactions between either nBuLi or PhLi and

1-chloronaphthalene (1a) in toluene at rt (Table 6.1) Surprisingly, the use of [Ni(cod)

]

(cod=1,5-cyclooctadiene) which has previously been shown to be effective for the

cross-coupling of (trimethylsilyl)methyllithium with aryl ethers,

gave no conversion into the

desired products 2a or 3a. ( entries 1a,b). Adding a phosphine ligand such as

1,2-bis(diphenylphosphino)ethane (dppe) to the nickel catalyst gave the same disappointing result

for

n

BuLi (entry 2a) and 51% conversion, along with dehalogenated side product 4a, for PhLi

(entry 2b).

Table 6.1 Reaction Optimization with nickel catalysts

Entrya R Catalyst Conv. (%)b

2a/3a: 4a:5ab 1a n-Bu Ni(COD)2 2 - 1b Ph 0 - 2a n-Bu Ni(COD)2/dppe 3 - 2b Ph 51 53:47:0 3a n-Bu NiCl2(DME) 5 - 3b Ph 39 85:15:0 4a n-Bu NiCl2(PPh3)2 40 42:40:18 4b Ph 30 90:10:0 5a n-Bu NiCl2(PCy3)2 68 25:60:15 5b Ph >99 68:30:2 6a n-Bu NiCl2(DME)/Xphos 69 15:46:23 6b Ph 33 67:33:0

7a n-Bu NiCl2(dppe) >99 93::7:0 7b Ph 86 73:25:2 8a n-Bu NiCl2(dppf) 85 52:35:8 8b Ph 92 79:15:6 9a n-Bu C1 >99 94:6:0 9b Ph >99 95:1:4 10a n-Bu C2 36 11:89:0 10b Ph 98 58:42:0 11a n-Bu C3 72 57:43:0 11b Ph >99 >99:0:0 11cc >99 >99:0:0 11dd >99 >99:0:0 (98% yield) 11ee 30 >99:0:0 12 n-Bu Pd-Peppsi-Ipent >99 86:14:0

[a] Conditions: n-Butyllithium (0.45 mmol, 1,6 M in hexanes diluted with toluene to a final concentration of 0.45 M) or phenyllithium (0.45 mmol, 1.8 M solution in dibutyl ether diluted with toluene to a final concentration of 0.5 M) was added to a solution of 2-chloronaphthalene (0.3 mmol) in toluene (1,5 mL) over 1 h. [b] Conversion and 2a/3a:4:5: ratios determined by GC analysis. [c] Using 0.5 mol% of catalyst. [d] 10 mmol (1.63 g) scale reaction using 1.5 mol% of catalyst. [e] using 0.25 mol% of catalyst.

Considering these results and the fact that [Ni(cod)

] requires rigorous air-free conditions,

hampering both large-scale applications and optimization efforts, we turned our attention to

nickel(II) catalysts. Low to moderate conversions and selectivities were observed when

[NiCl

(dme)] (dme=dimethoxyethane) or [NiCl

(PPh

)

] were used (entries 3a-4b). Using

more electron rich and bulky phosphines (PCy

or XPhos

) resulted in higher conversion,

but the selectivity for 2a or 3a remained unsatisfactory (entries 5a-6b). Subsequently, we

investigated the effect of common bidentate phosphines, which have been reported to impart

high activity in related nickel-catalyzed cross-coupling reactions with other organometallics.

The use of [NiCl

(dppe)]

and [NiCl

(dppf)] (dppf=1,1'-bis(diphenylphosphino)ferrocene)

resulted in even higher conversions but dehalogenation remained substantial (entries 7a-8b).

Encouraged by these results, we studied variations in the ligand structure and we found that

the

use

of

commercial

nickel

complex

[NiCl

(depe)]

(C1;

depe=bis(diethylphosphino)ethane

bearing a bidentate alkylphosphine, led to full

conversion in the reaction with both

n

BuLi and PhLi with excellent selectivity toward the

cross-coupled products 2a or 3a (entries 9a,b). The nitrogen-based tridentate ligand C2

(entries 10a,b)

was not efficient for this transformation. Remarkably, the use of

Pd-PEPPSI-IPent (entry 12), as well as other palladium-based catalysts (not shown) in the

reaction of nBuLi gave rise to lower selectivity than that observed with the nickel catalyst C1.

We then explored the effectiveness of catalyst C1 with respect to a less reactive

non-π-extended aryl chloride, such as 1-butyl-4-chlorobenzene 1b (Scheme 6.2), but incomplete

conversion was observed in the case of PhLi, alongside a large amount of n-butylbenzene 4b.

As neither elevated nor lower temperatures improved this result, further screening of nickel

catalysts was carried out. We found that the use of commercially available nickel(II) complex

[NiCl

(PPh

)IPrC3,

bearing a N-heterocyclic carbene, was key to restoring the conversion

(87 % yield of isolated product) and selectivity (98:2) toward 2b. Catalyst C3 also gave full

conversion with high selectivity in the reaction of 1a with PhLi (Table 1, entry 11b), allowing

a decrease in the catalyst loading to 0.5 mol % (entry 11c). Moreover, when this reaction was

performed on a larger scale (10 mmol, 1.63g) in the presence of 1.5 mol % of catalyst C3, 2a

was still obtained as the exclusive product in excellent yield (98% isolated product). The use

of C3 in the reaction of 1a with nBuLi afforded the desired compound 3a, albeit with

decreased conversion and selectivity compared to C1 (Table 6.1, entry 11a).

With two optimized catalyst systems (C3 for (hetero)aryllithium and C1 for alkyllithium,

respectively) we examined the generality of this reaction. A broad range of aryl bromides,

chlorides, fluorides, and methoxyarenes could be coupled with PhLi, using C3 as catalyst

(Scheme 6.2). Polyaromatic compounds showed high reactivity and could be transformed into

the coupled products in good to high yields with excellent selectivity (2a, 2c-e). Substrates

containing two aromatic groups could also be transformed selectively (2f, X=Br, and 2g,

X=Br, F).

Scheme 6.2. Nickel-catalyzed cross-coupling of phenyllithium with (hetero)aryl (pseudo)halides. [a] Conditions: Phenyllithium (0.75 mmol, 1.8 M solution in dibutyl ether diluted with toluene to a final concentration of 0.6 M) was added to a solution of organic (pseudo)halide (0.5 mmol) in toluene (1.5 mL) over 1 h. Isolated yields after column chromatography. [b] Reaction performed at 0 °C.

It is important to note that high reactivity was also found for simple phenyl halides or methyl

ethers, regardless of the electronic nature or the leaving group employed (2i-o). As shown for

2g, 2j, and 2k, the presence of an ortho substituent did not significantly hamper the

cross-coupling. A substrate containing an olefin (1h) was also readily converted into the

corresponding product 2h with high selectivity (Scheme 2). Trifluoromethylated compounds,

which are very important in the agrochemical and pharmaceutical industries,

were also

suitable substrates, furnishing the corresponding products 2l and 2m in moderate to good

yield. As expected, C-Br and C-Cl bonds are more reactive than a C-O bond, allowing the

selective coupling of 4-bromo- or 4-chloroanisole at 0°C, leaving the methoxy group

untouched (2n). Only dehalogenation was observed in the reaction of

3-bromo-N,N-dimethylaniline 1o with PhLi. However, the corresponding chloride provided biaryl 2o in 45

% yield. A sulfur-containing heterocycle was also coupled, affording compound 2p with high

selectivity.

We next examined the compatibility of our catalytic system with the most efficient procedures

to access (hetero)aryllithium species, which include direct metalation

and halogen--lithium

exchange

(Scheme 6.3). Hindered bis-ortho-substituted (2,6-dimethoxyphenyl)lithium,

prepared by directed lithiation, undergoes cross-coupling with 1-chloronaphthalene and

electron-rich 4-bromoanisole providing biaryls 2q and 2r, without the need to increase the

temperature or reaction time. Moreover a methoxymethyl (MOM) protecting group could be

tolerated at the ortho position of the organolithium reagent, allowing for an easy

ortho-lithiation/cross-coupling sequence to afford the corresponding MOM-protected phenol (2s,

2t). Furyllithium, obtained by direct lithiation of furan, smoothly couples to provide

compounds 2u-w with good yields and high selectivities. Organolithium compounds, obtained

through halogen-lithium exchange, could also be used as exemplified in the preparation of 2x

and 2z.

Scheme 6.3. Nickel-catalyzed cross-coupling of (hetero)aryllithium reagents with aryl halides. Conditions: Aryl-Li (0.75 mmol, diluted with toluene to reach 0.45 M concentration) was added to a solution of organic halide (0.5 mmol) in toluene (1.5 mL) over 1 h. Selectivity 2 vs dehalogenated + homocoupled >90%. Isolated yields after column chromatography.

Importantly, commercially available 2-thienyllithium, which, according to our previous

study,

requires the addition of stoichiometric amounts of tetramethylethylenediamine

(TMEDA) as activating agent and elevated temperatures, reacted with chloro- and

1-bromonaphthalene at room temperature without the use of any additive (2y).

With an efficient procedure for aryl-aryl cross-coupling in hand, we turned our attention to the

use of alkyllithium compounds , applying catalyst C1 (Table 6.2).

A range of polyaromatic

chlorides and fluorides were regioselectively alkylated at position 1 or 2, indicating that

benzyne intermediates, formed through 1,2-elimination, are not involved.

Table 6.2. Nickel-catalyzed cross-coupling of alkyllithium compounds

Entrya Aryl halide Alkyllithium Yield (%)b

1 (3a) 1-chloronaphthalene EtLi 65 2 (3b) n-BuLi 78 3 (3c) n-HexLi 87 4 (3d) iPrLic 63 5 (3e) 2-chloroanthracene EtLi 67 6 (3f) n-HexLi 39 7 (3g) 1-chloroanthracene EtLi 94 8 (3h) n-BuLi 84 9 (3i) n-HexLi 85 10 (3j) iPrLic 44 11 (3k) CycloPrLi 66 12 (3b) 1-fluoronaphthalene n-BuLi 76 13 (3a) EtLi 66 14 (3d) iPrLi 63

[a] Conditions: AlkylLi (0.45 mmol, diluted with Toluene to reach 0.45 M concentration) was added to a solution of organic halide (0.3 mmol) in toluene (2 mL) over 1 h. GC selectivity >95%. [b] Isolated yields after column chromatography. [c] GC selectivity > 80%.

No isomerization of the alkyl moiety and less than 5% of reduced product were observed

when primary alkyllithium reagents were employed, demonstrating that competing β-hydride

elimination/dissociation was almost completely inhibited. Importantly, the use of EtLi, which

was unreactive in our previous palladium-based systems, afforded the corresponding products

(3a, 3e, 3g) in good yields and nearly perfect selectivity. These results highlight how

alternative metals such as nickel, besides being inexpensive, can also display complementary

reactivity to palladium. The reaction using

i

PrLi, which contains an increased number of

β-hydrogen atoms, proceeds without isomerization, although a minor amount of the reduced

product was formed (entries 4 and 14).

Cyclopropyllithium,

prepared from cyclopropyl

bromide and lithium metal, also provided the coupled product with high selectivity without

any ring-opened side products (entry 11).

6.3 Conclusions

In summary, we have described for the first time how a range of (hetero)aryl and alkyllithium

compounds can be employed in cross-coupling reactions with aryl bromides, chlorides,

fluorides, and aromatic ethers, by using nickel as catalyst. The reaction takes place under mild

conditions (RT) with a broad scope of organolithium compounds and substrates, enabling

transformations that were proven difficult with palladium catalysts, such as the cross-coupling

of alkyllithium reagents bearing β-hydrogen with aryl chlorides and the use of EtLi as a

coupling partner. The low cost and availability of both organolithium reagents and nickel

catalysts, together with the selectivity of the novel method presented herein, make it a

valuable alternative with lower environmental impact for atom-economic formation of C-C

bonds

6.4 References

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Acc. Chem. Res. 2015, 48, 1717; For nickel-catalyzed cross-coupling reactions of benzylic ethers and

esters see: g) E. J. Tollefson, L. E. Hanna, E. R. Jarvo, Acc. Chem. Res. 2015, 48, 2344.

[7] a) For a recent example using B2nep2 as nucleophile see: X.-W. Liu, J. Echavarren, C. Zarate, Ruben Martin J. Am. Chem. Soc. 2015, 137, 12470.; b) F. Zhu, Z.-X. Wang J. Org. Chem. 2014, 79, 4285. and references cited therein.; c) A. D. Sun, K. Leung, A. D. Restivo, N. A. LaBerge, H. Takasaki, J. A. Love, Chem. Eur. J. 2014, 20, 3162.; d) H. Guo, F. Kong, K.-I. Kanno, J. He, K. Nakajima, T. Takahashi, Organometallics 2006, 25, 2045.

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[10] a) M. Giannerini, M. Fañanás-Mastral, B. L. Feringa, Nature Chem. 2013, 5, 667; b) M. Giannerini, V. Hornillos, C. Vila, M. Fañanás-Mastral, B. L. Feringa, Angew. Chem. Int. Ed. 2013, 52, 13329; c) C. Vila, M. Giannerini, V. Hornillos, M. Fañanás-Mastral, B. L. Feringa, Chem. Sci. 2014, 5,

1361; d) V. Hornillos, M. Giannerini, C. Vila, M. Fañanás-Mastral, B. L. Feringa, Chem. Sci. 2015, 6, 1394.

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Acknowledgements

This work described in this chapter was carried out together with Dr. Valentin Hornillos and Dr. Jean Baptiste Gualtierotti

6.5 Experimental section

Chromatography: Merck silica gel type 9385 230-400 mesh, TLC: Merck silica gel 60, 0.25 mm. Components were visualized by UV and potassium permanganate staining. Conversion of the reaction were determined by GC-MS (GC, HP6890: MS HP5973) with an HP1 or HP5 column (Agilent Technologies, Palo Alto, CA). Mass spectra were recorded on an AEI-MS-902 mass spectrometer (EI+) or a LTQ Orbitrap XL (ESI+). 1H- and 13C-NMR were recorded on a Varian AMX400 (400 and 101 MHz, respectively) or a Varian VXR300 (300 and 75 MHz, respectively) using CDCl3 as solvent. Chemical shift values are reported in ppm with the solvent resonance as the internal standard (CHCl3: δ 7.26 for 1H, δ 77.0 for 13C). Data are reported as follows: chemical shifts, multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, br = broad, m = multiplet), coupling constants (Hz), and integration. All reactions were carried out under nitrogen or argon atmosphere using oven dried glassware and using standard Schlenk techniques. Diethyl ether, tetrahydrofuran and toluene were used from the solvent purification system (MBRAUN SPS systems, MB-SPS-800). n-Hexane was dried and distilled over sodium. All starting aryl bromides, chlorides and fluorides as well as organolithium precursors were commercially available from Aldrich, Alfa-Aesar, Acros or TCI Europe, unless otherwise indicated. PhLi (1.8 M in n-Bu2O), n-BuLi (1.6 M in n-hexane), t-BuLi (1.7 M in pentane), EtLi (0.5 M in benzene:cyclohexane), n-HexLi (0.7 M in pentane), 2-Thienyllithium (1.0 M in THF/hexanes) and i-PrLi (2.3 M in hexane) were commercially available from Aldrich and were diluted to 0.45 M with dry toluene before use. Pd-Peppsi-i-Pent, all nickel catalysts, except C3, and ligands were commercially available from Aldrich. C3 was available from TCI Europe. All catalysts, ligands and reagents were used as received without further purification.

B. Preparation of organolithium reagents:

4-Methoxy-phenyllithium

In a dry Schlenk flask 4-bromoanisole (623 μl, 5.0 mmol, 1.0 equiv) was dissolved in dry THF (5.55 mL, 0.90 M) and the solution was cooled down to -78 °C. t-BuLi (5.88 ml, 10 mmol, 2.0 equiv) was added slowly and the solution was stirred for 1 h. Then the temperature of the solution was allowed to reach room temperature and the solution of organolithium regents was used without further dilution (final concentration 0.44 M).

Furyllithium

Furan (363 μl, 5.0 mmol, 1.0 equiv) was dissolved in THF (7.93 mL, 0.63 M) and the solution was cooled down to -40 °C. n-BuLi (3.13 ml. 5 mmol, 1 equiv) was added slowly. Then the solution was allowed to reach room temperature and stirred for 1 h and used without further dilution (final concentration 0.45 M).

Cyclopropyllithium

In a dry Schlenk flask, lithium shot (63 mg, 9 mmol, 1.8 equiv) was suspended in dry ether (1.38 mL, 6.5 M) at room temperature. Then bromocyclopropane (401 μL, 5 mmol, 1 equiv) was dissolved in ether (1.39 mL, 3.6 M) and added slowly over 30 min using a syringe pump. After the addition the mixture was stirred for 15 min. The solution was then diluted before use with toluene (8.31 ml) to reach a final concentration of 0.45 M.

2-Methoxymethoxy-phenyllithium.

In a dry Schlenk flask (methoxymethoxy)benzene1 (690 mg, 5.0 mmol, 1 equiv) was dissolved in dry THF (15.15 mL, 0.33 M) and the solution was cooled down to -78 °C. t-BuLi (2.94 ml, 5 mmol, 1 equiv) was added slowly and the solution was stirred for 1 h. Then the solution was allowed to reach room temperature and used without further dilution (final concentration 0.28M).

2.6-Dimethoxyphenyllithium

In a dry Schlenk flask 1,3-dimethoxybenzene (657 μl, 5.0 mmol, 1.0 equiv) was dissolved in dry THF (2.5 mL, 2 M) and the solution was cooled down to -10 °C. n-BuLi (3.13 ml. 5 mmol, 1 equiv) was added slowly and the solution was stirred for 30 min. Then the solution was allowed to reach room temperature. The solution was then diluted before use with toluene (5.48 ml) to reach a final concentration 0.45 M.

C. General Procedures for the Cross-Coupling of Aryllithium Reagents with Arylhalides or Arylmethoxides.

In a dry Schlenk flask, [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene]triphenylphosphine nickel(II) dichloride C3 (19.51 mg, 0.025 mmol, 5 mol%) and the substrate (0.5 mmol, 1 equiv) were dissolved in dry toluene (1.5 ml, 0.33 M) and the mixture was stirred at room temperature. The corresponding lithium reagent (0.75 mmol, 1.5 equiv) was slowly added over 1 h by syringe pump. When the addition was completed a saturated aqueous solution of NH4Cl was added to the reaction and the mixture was extracted three times with ethyl acetate. The organic phases were combined, washed with brine, dried over sodium sulfate and evaporated to dryness under vacuum to afford the crude product which was then purified by column chromatography.

D. General Procedures for the Cross-Coupling of Alkyllithium Reagents with Arylhalides.

In a dry Schlenk flask, dichloro[1,2-bis(diethylphosphino)ethane]nickel(II) C1 (7.0 mg, 0.021 mmol, 5 mol%) and the substrate (0.3 mmol, 1 equiv) were dissolved in dry toluene (2 ml, 0.15 M) and the mixture was stirred at room temperature. The corresponding lithium reagent (0.45 mmol, 1.5 equiv) was slowly added over 1 h by syringe pump. When the addition was completed a saturated aqueous solution of NH4Cl was added to the reaction flask and the mixture was extracted three times with ethyl acetate. The organic phases were combined, washed with brine, dried over sodium sulfate and evaporated to dryness under vacuum to afford the crude product which was then purified by column chromatography.

1

E. Experimental Details and Spectral Data of Compounds

2a) 1-phenylnaphthalene Purified by FCC using pentane. Yield: 88% (from 1-bromonaphthalene), 75% (from 1-fluoronaphthalene), 93% (from 1- chloronaphthalene [>85% GCMS, 9 to 1 mixture with 2-chloronaphthalene], isolated as a 90/10 mixture with 2-phenylnaphthalene) Molecular Formula: C16H12 1H NMR (300 MHz, CDCl3) δ 7.97-7.91 (m, 2H), 7.91-7.86 (m, 1H), 7.58-7.41 (m, 9H). 13C NMR (75MHz, CDCl3) δ 140.7, 140.2, 133.8, 131.6, 130.1, 128.2, 128.2, 127.6, 127.2, 126.9, 126.0, 126.0, 125.7, 125.4. Spectral data match those reported in the literature. 2

2b) 4-butyl-1,1'-biphenyl Purified by FCC using pentane. Isolated with trace biphenyl originating from the commercial Ph-Li used. Yield: 87% Molecular Formula: C16H18 1H NMR (400 MHz, CDCl3) δ 7.68 (dd, J = 8.1, 3.9 Hz, 2H), 7.60 (d, J = 7.8 Hz, 2H), 7.51 (q, J = 7.2 Hz, 2H), 7.45-7.37 (m, 1H), 7.34 (d, J = 7.8 Hz, 2H), 2.74 (t, J = 7.6 Hz, 2H), 1.73 (p, J = 7.6 Hz, 2H), 1.49 (h, J = 7.6 Hz, 2H), 1.05 (t, J = 7.6 Hz, 3H). 13C NMR (101MHz, CDCl3) δ 142.0, 141.2, 138.5, 128.8, 128.7, 126.9, 126.9, 126.9, 35.3, 33.6, 22.4, 14.0. Spectral data match those reported in the literature.2

2c) 9-phenylphenanthrene Purified by FCC using pentane Yield: 82% Molecular Formula: C20H14 1H NMR (300 MHz, CDCl3) δ 8.82 (dd, J = 8.3, 1.3 Hz, 1H), 8.77 (dd, J = 8.0, 1.5 Hz, 1H), 7.99 (dd, J = 8.3, 1.3 Hz, 1H), 7.94 (dd, J = 8.0, 1.5 Hz, 1H), 7.79-7.43 (m, 10H). 13C NMR (75MHz, CDCl3) δ 140.8, 138.7, 131.5, 131.1, 130.6, 130.0, 129.9, 128.6, 128.3, 127.5, 127.3, 126.9, 126.8, 126.5, 126.5, 126.4, 122.9, 122.5. Spectral data match those reported in the literature.3

2

B. L. Feringa, Org. Lett., 2013, 15, 5114-5117. 7 3

F. Glorius, Chem. Sci., 2015, 6, 1816-1824. 4

2d) 2-phenylanthracene Purified by FCC using pentane. Yield: 43% Molecular Formula: C20H14 1H NMR (300 MHz, CDCl3) δ 8.48 (s, 1H), 8.45 (s, 1H), 8.21 (s, 1H), 8.09 (d, J = 8.8 Hz, 1H), 8.06-7.98 (m, 2H), 7.82-7.74 (m, 3H), 7.56-7.44 (m, 4H), 7.41 (t, J = 7.3 Hz, 1H). 13C NMR (75MHz, CDCl3) δ 141.0, 137.8, 132.1, 131.9, 131.8, 130.9, 128.9, 128.7, 128.2, 128.1, 127.4, 127.3, 126.6, 126.0, 125.7, 125.5, 125.5, 125.4. Spectral data matcher known literature reference.4

2e) 2-phenylnaphthalene Purified by FCC using pentane. Yield: 76% Molecular Formula: C16H12 1H NMR (400 MHz, CDCl3) δ 8.10 (d, J = 1.9 Hz, 1H), 8.00-7.88 (m, 3H), 7.84-7.74 (m, 3H), 7.54 (tt, J = 6.5, 2.5 Hz, 4H), 7.46-7.39 (m, 1H). 13C NMR (101MHz, CDCl3) δ 141.2, 138.4, 133.7, 132.7, 128.9, 128.5, 128.2, 127.7, 127.5, 127.4, 126.3, 126.0, 125.8, 125.6. Spectral data match those reported in the literature. 2

2f) 1,1':4',1''-terphenyl Purified by preparatory layer chromatography (PLC Silica gel 60 F254, 2mm) using pentane. Yield: 61% Molecular Formula: C18H14 1H NMR (300 MHz, CDCl3) δ 7.68 (s, 4H), 7.67-7.62 (m, 4H), 7.51-7.42 (m, 4H), 7.36 (t, J = 7.4 Hz, 2H). 13C NMR (75MHz, CDCl3) δ 140.9, 140.3, 129.0, 127.6, 127.5, 127.2. Spectral data match those reported in the literature . 5

2g) o-Terphenyl Purified by preparatory layer chromatography (PLC Silica gel 60 F254, 2mm) using pentane. Yield: 61% (from 4-bromobiphenyl), 56% (from 4-fluorobiphenyl) Molecular Formula: C18H14 1

H NMR (300 MHz, CDCl3) δ 7.43 (s, 4H), 7.26-7.17 (m, 6H), 7.17-7.11 (m, 4H). 13C NMR (75 MHz, CDCl3) δ 141.4, 140.5, 130.5, 129.8, 127.8, 127.4, 126.4. Spectral data match those reported in the literature.6

5

J.-X. Wang, Adv. Synth. Catal., 2008, 350, 315-320. 9

6 _{SDBS database No. 1198 (http://sdbs.db.aist.go.jp, National Institute of Advanced Industrial Science and} Technology, 30.07.2015).

2h) (E/Z)-4-methoxy-4'-(prop-1-en-1-yl)-1,1'-biphenyl The reaction was run with 7.5 mol% of catalyst and at 40°C. Purified by FCC using pentane/dichloromethane (95:5-90:10). 1-bromo-4-(prop-1-en-1-yl)benzene was used as a 1:1 mixture of E/Z isomers and the product was obtained as a 1:1 mixture of E/Z isomers. 7 Yield: 56% Molecular Formula: C16H16O 1H NMR (300 MHz, CDCl3) δ 7.64-7.48 (m, 4H), 7.40 (d, J = 8.5 Hz, 1H) , 7.39 (d, J = 8.5 Hz, 1H), 7.01 (d, J = 8.8 Hz, 1H) , 6.99 (d, J = 8.8 Hz, 1H), 6.55-6.40 (m, 1H), 6.29 (dq, J = 15.7, 6.5 Hz, 0.45H), 5.84 (dq, J = 11.5, 7.2 Hz, 0.55H), 3.87 (s, 1.5H), 3.87 (s, 1.5H), 1.98 (dd, J = 7.2, 1.8 Hz, 1.6H), 1.93 (d, J = 6.5 Hz, 1.4H). 13C NMR (75MHz, CDCl3) δ 159.1, 159.0, 139.0, 138.7, 136.3, 136.0, 133.4, 133.3, 130.6, 129.4, 129.2, 127.9, 127.8, 126.7, 126.6, 126.3, 126.1, 125.5, 114.1, 114.1, 55.3, 18.5, 14.7. HRMS: Calculated for C16H17O [M+H]+ 225.1270; found 225.1274.

2i) 4-methyl-1,1'-biphenyl Purified by FCC using pentane. Isolated as a 70:30 mixture (GCMS) with biphenyl originating from commercial phenyl lithium. Yield: 43% (from 4-fluorotoluene), 39% (from 4-methoxytoluene). Molecular Formula: C13H12 1H NMR (400 MHz, CDCl3) δ 7.67-7.59 (m, 5H), 7.56-7.50 (m, 3H), 7.51-7.42 (m, 5H), 7.41-7.31 (m, 2H), 7.31-7.24 (m, 2H), 2.42 (s, 3H). 13C NMR (101MHz, CDCl3) δ 141.1, 138.3, 137.0, 129.5, 128.7, 127.0, 127.0, 127.0, 21.1. Spectral data match those reported in the literature.8

2j) 2-methyl-1,1'-biphenyl Purified by FCC using pentane. Isolated as a 78:22 mixture (GCMS) with biphenyl originating from the commercial phenyl lithium. Yield: 94% Molecular Formula: C13H12 1H NMR (400 MHz, CDCl3) δ 7.68 (d, J = 7.6 Hz, 1H), 7.56-7.46 (m, 3H), 7.46-7.38 (m, 3H), 7.38-7.29 (m, 4H), 2.36 (s, 3H). 13C NMR (101MHz, CDCl3) δ 155.1, 141.9, 135.3, 130.3, 129.8, 129.2, 128.0, 128.0, 126.7, 125.7, 20.5. Spectral data match those reported in the literature. 8

k) 2,4-dimethyl-1,1'-biphenyl Purified by FCC using pentane. Isolated as a 75:25 mixture (GCMS) with biphenyl originating from the commercial phenyl lithium. Yield: 94% Molecular Formula: C14H14 1H NMR (400 MHz, CDCl3) δ 7.68-7.62 (m, 1H), 7.53-7.33 (m, 2H), 7.27-7.13 (m, 1H), 2.40 (s, 3H), 2.22 (s, 1H). 13C NMR (101MHz, CDCl3) δ 142.6, 142.3, 141.3, 137.2, 134.0, 129.4, 128.9, 128.8, 128.0, 127.7, 127.3, 127.2, 126.6, 125.3, 20.8, 17.0. Spectral data match those reported in the literature. 9

2l) 3-(trifluoromethyl)-1,1'-biphenyl Purified by preparatory layer chromatography (PLC Silica gel 60 F254, 2mm) using pentane. Yield: 51% Molecular Formula: C13H9F3 1H NMR (300 MHz, CDCl3) δ 7.89 (s, 1H), 7.85-7.79 (m, 1H), 7.71-7.57 (m, 4H), 7.57-7.41 (m, 3H). 13C NMR (75MHz, CDCl3) δ. 142.1, 139.8, 131 (q, J = 31.8 Hz), 130.4, 129.3, 129.0, 128.1, 127.2, 124.2 (q, J = 272.1 Hz), 124.0 (m) Spectral data match those reported in the literature10 .

2m) 4-(trifluoromethyl)-1,1'-biphenyl Purified by FCC using pentane. Yield: 88% (from 1-bromo-4-(trifluoromethyl)benzene), 81% (from 1-chloro-4- 1-bromo-4-(trifluoromethyl)benzene), 25% (1-fluoro-4-(trifluoromethyl)benzene). Molecular Formula: C13H9F3 1H NMR (300 MHz, CDCl3) δ 7.70 (s, 4H), 7.64-7.59 (m, 2H), 7.52-7.45 (m, 2H), 7.45-7.38 (m, 1H). 13C NMR (75MHz, CDCl3) δ 144.7, 139.8, 129.0, 128.2, 127.4, 127.3, 125.7, 125.6. Spectral data match those reported in the literature. 2

2n) 4-methoxy-1,1'-biphenyl Purified by FCC using pentane. Yield: 86% (From 4-bromoanisole), 66% (from 4-chloroanisole). Molecular Formula: C13H12O 1H NMR (300 MHz, CDCl3) δ 7.65-7.50 (m, 4H), 7.52-7.40 (m, 2H), 7.39-7.29 (m, 1H), 7.07-6.93 (m, 2H), 3.87 (d, J = 1.7 Hz, 3H). 13C NMR (75MHz, CDCl3) δ 159.2, 140.8, 133.8, 128.7, 128.2, 126.7, 126.7, 114.2, 55.3. Spectral data match those reported in the literature. 2

7

K. U. Ingold, J. Am. Chem. Soc., 2002, 124, 6362-6366. 10 8

Z. Zhang, Angew. Chem. Int. Ed., 2015, 54, 4079-4082. 9

2o) N,N-dimethyl-[1,1'-biphenyl]-3-amine Purified by FCC using Pentane/Toluene (75:25). Yield: 45% Molecular Formula: C14H15N 1H NMR (300 MHz, CDCl3) δ 7.69-7.61 (m, 2H), 7.53-7.44 (m, 2H), 7.43-7.33 (m, 2H), 7.00-6.92 (m, 2H), 6.82-6.72 (m, 1H), 3.07 (s, 6H). 13C NMR (75 MHz, CDCl3) δ 150.7, 142.2, 142.1, 129.3, 128.5, 127.3, 127.0, 116.0, 111.7, 111.6, 40.7. Spectral data match those reported in the literature. 2

2p) 3-phenylbenzo[b]thiophene Purified by FCC using pentane. Yield: 65% Molecular Formula: C14H10S 1H NMR (400 MHz, CDCl3) δ 7.96-7.89 (m, 2H), 7.63-7.57 (m, 2H), 7.53-7.46 (m, 2H), 7.46-7.36 (m, 4H). 13C NMR (101MHz, CDCl3) δ 140.7, 138.1, 137.9, 136.0, 128.7, 127.5, 124.4, 124.3, 123.4, 122.9, 122.9. Spectral data match those reported in the literature. 12

2q) 1-(2,6-dimethoxyphenyl)naphthalene Purified by FCC using pentane. Yield: 45% Molecular Formula: C18H16O2 1H NMR (400 MHz, CDCl3) δ 7.90 (m, 2H), 7.58 (dd, J = 8.2, 7.0 Hz, 1H), 7.55-7.34 (m, 5H), 6.75 (d, J = 8.2 Hz, 2H), 3.66 (s, 6H). 13C NMR (101MHz, CDCl3) δ 158.4, 133.5, 132.7, 132.6, 129.1, 128.2, 128.0, 127.4, 126.0, 125.5, 125.4, 125.34, 117.6, 104.1, 55.9. Spectral data match those reported in the literature. 13

2r) 2,4',6-trimethoxy-1,1'-biphenyl Purified by FCC using pentane. Yield: 30% Molecular Formula: C15H16O3 1H NMR (300 MHz, CDCl3) δ 7.42-7.15 (m, 3H), 7.12-6.87 (m, 2H), 6.68 (d, J = 8.3 Hz, 2H), 3.87 (s, 3H), 3.77 (s, 6H). 13C NMR (75MHz, CDCl3) δ 158.3, 157.8, 131.9, 128.3, 126.1, 119.1, 113.2, 104.2, 55.9, 55.1. Spectral data match those reported in the literature. 14

11

M. Nakamura, J. Am. Chem. Soc., 2007, 129, 9844-9845. 12

S. Oi, Org. Lett., 2012, 14, 6186-6189. 14 13

B. L. Feringa, Angew. Chem. Int. Ed., 2013, 52, 13329-13333. 14

A. Wagner, Org. Lett., 2007, 9, 1781-1783. 15

2s) 1-(2-(methoxymethoxy)phenyl)naphthalene Purified by FCC using pentane. Yield: 72% Molecular Formula: C18H16O2 1H NMR (400 MHz, CDCl3) δ 7.90-7.75 (m, 2H), 7.59 (d, J = 8.3 Hz, 1H), 7.50 (t, J = 7.5 Hz, 1H), 7.44 (t, J = 7.5 Hz, 1H), 7.41-7.32 (m, 3H), 7.28 (d, J = 8.3 Hz, 1H), 7.23 (d, J = 6.6 Hz, 1H), 7.11 (t, J = 7.5 Hz, 1H), 4.97 (d, J = 6.8 Hz, 1H), 4.93 (d, J = 6.8 Hz, 1H), 3.18 (s, 3H). 13C NMR (101MHz, CDCl3) δ 154.8, 137.0, 133.3, 132.1, 131.9, 130.6, 129.0, 128.0, 127.6, 127.2, 126.4, 125.6, 125.5, 125.3, 121.9, 115.1, 94.6, 55.9. Spectral data match those reported in the literature. 2

2t) 2,4',6-trimethoxy-1,1'-biphenyl Purified by FCC using pentane. Yield: 30% Molecular Formula: C15H16O3 1H NMR (400 MHz, CDCl3) δ 7.56-7.44 (m, 2H), 7.34 (dd, J = 7.6, 1.8 Hz, 1H), 7.32-7.25 (m, 1H), 7.24- 7.20 (m, 1H), 7.15-7.04 (m, 1H), 7.01-6.92 (m, 2H), 5.14 (s, 2H), 3.87 (s, 3H), 3.42 (s, 3H). 13

C NMR (101MHz, CDCl3) δ 158.7, 154.2, 131.5, 131.0, 130.8, 130.6, 128.2, 122.3, 115.7, 113.5, 95.1, 56.1, 55.3. Spectral data match those reported in the literature. 15

2u) 2-(4-methoxyphenyl)furan Purified by FCC using pentane. Yield: 73% Molecular Formula: C11H10O2 1H NMR (400 MHz, CDCl3) δ 7.61 (d, J = 8.2 Hz, 2H), 7.43 (s, 1H), 6.93 (d, J = 8.2 Hz, 1H), 6.56-6.48 (m, 1H), 6.45 (m, 1H), 3.84 (s, 3H). 13C NMR (101MHz, CDCl3) δ 159.0, 154.0, 141.4, 125.2, 124.0, 114.1, 111.5, 103.4, 55.3. Spectral data match those reported in the literature. 16

2v) 2-(anthracen-2-yl)furan Purified by FCC using pentane. Yield: 65% Molecular Formula: C18H12O 1H NMR (400 MHz, CDCl3) δ 8.43 (s, 1H), 8.38 (s, 1H), 8.31 (s, 1H), 8.00 (m, 3H), 7.75 (d, J = 8.8 Hz, 1H), 7.56 (s, 1H), 7.52-7.38 (m, 2H), 6.81 (d, J = 3.2 Hz, 1H), 6.60-6.50 (m, 1H). 13C NMR (101MHz, CDCl3) δ

154.1, 142.5, 132.2, 131.8, 131.6, 130.8, 128.7, 128.2, 128.1, 127.4, 126.5, 126.2, 125.6, 125.4, 122.3, 121.8, 111.9, 106.0. Spectral data match those reported in the literature. 17

15

B. L. Feringa, Org. Lett., 2015, 17, 62-65. 16 16

B. L. Feringa, Chem. Eur. J., 2014, 20, 13078-13083. 17

C.-M. Che, Org. Lett., 2006, 8, 325-328. 17

2w) 2-(naphthalen-2-yl)furan Purified by FCC using pentane. Yield: 43% Molecular Formula: C14H10O 1

H NMR (300 MHz, CDCl3) δ 8.17 (s, 1H), 8.00-7.69 (m, 4H), 7.58-7.37 (m, 3H), 6.79 (d, J = 3.4 Hz, 1H), 6.54 (dd, J = 3.4, 1.8 Hz, 1H). 13C NMR (75MHz, CDCl3) δ 154.1, 142.3, 133.6, 132.7, 128.4, 128.2, 128.2, 127.8, 126.5, 125.9, 122.3, 122.1, 111.8, 105.6. Spectral data match those reported in the literature. 16

2x) 1-(4-methoxyphenyl)naphthalene Purified by FCC using pentane. Yield: 70% Molecular Formula: C17H14O 1H NMR (400 MHz, CDCl3) δ 7.98 (d, J = 8.4 Hz, 1H), 7.94 (d, J = 8.2 Hz, 1H), 7.88 (d, J = 8.2 Hz, 1H), 7.58-7.54 (m, 1H), 7.52 (dd, J = 8.4, 1.6 Hz, 1H), 7.50-7.43 (m, 4H), 7.07 (d, J = 8.6 Hz, 2H), 3.92 (s, 3H). 13C NMR (101MHz, CDCl3) δ 159.0, 139.9, 133.9, 133.2, 131.9, 131.1, 128.3, 127.4, 126.9, 126.1, 125.9, 125.7, 125.4, 113.8, 55.4. Spectral data match those reported in the literature. 18

2y) 2-(naphthalen-yl)thiophene Purified by FCC using pentane. Yield: 79% (From 1-chloronaphtalene), 89% (From 1-bromonapththalene) Molecular Formula: C14H10S 1H NMR (400 MHz, CDCl3) δ 8.35-8.25 (m, 1H), 7.98-7.93 (m, 1H), 7.91 (dt, J = 8.2, 1.2 Hz, 1H), 7.64 (dd, J = 7.1, 1.2 Hz, 1H), 7.60-7.51 (m, 3H), 7.48 (dd, J = 5.1, 1.2 Hz, 1H), 7.31 (dd, J = 3.5, 1.2 Hz, 1H), 7.24 (dd, J = 5.1, 3.5 Hz, 1H). 13C NMR (101MHz, CDCl3) δ 141.8, 133.8, 132.4, 131.9, 128.4, 128.3, 128.2, 127.4, 127.2, 126.4, 126.0, 125.7, 125.6, 125.2. Spectral data match those reported in the literature. 16

2z) 2-(4-methoxyphenyl)naphthalene Purified by FCC using pentane/dichloromethane (90:10-85:15). Yield: 80% Molecular Formula: C17H14O 1_{H NMR (300 MHz, CDCl3) δ 8.04 (d, J = 2.0 Hz, 1H), 7.99-7.83}

(m, 3H), 7.76 (dd, J = 8.5, 1.9 Hz, 1H), 7.73-7.66 (m, 2H), 7.61-7.38 (m, 2H), 7.15-6.88 (m, 2H), 3.90 (s, 3H). 13C NMR (75MHz, CDCl3) δ 159.4, 138.3, 133.9, 133.7, 132.4, 128.5, 128.5, 128.2, 127.7, 126.3, 125.8, 125.5, 125.1, 114.4, 55.5. Spectral data match those reported in the literature. 19

18

L. X. Shao, J. Organomet. Chem., 2011, 696, 3741-3744. 18 19

B. Jiang, Org. Lett., 2015, 17, 1942-1945. 19

3a) 1-ethylnaphthalene Purified by FCC using pentane. Yield: 66% (from 1-fluoronaphthalene), 65% (isolated as a 88 to 12 mixture with 2-isopropylnaphthalene when starting from 1-chloronaphthalene, >85% GCMS, 9 to 1 mixture with 2- chloronaphthalene) Molecular Formula: C12H12 1H NMR (300 MHz, CDCl3) δ 8.12 (q, J = 8.3 Hz, 1H), 7.92 (d, J = 7.1 Hz, 1H), 7.77 (d, J = 8.3 Hz, 1H), 7.62-7.44 (m, 3H), 7.41 (d, J = 7.1 Hz, 1H), 3.18 (d, J = 7.9 Hz, 2H), 1.45 (t, J = 7.8 Hz, 3H). 13C NMR (75MHz, CDCl3) δ 140.2, 133.8, 131.8, 128.7, 126.4, 125.8, 125.6, 125.4, 124.8, 123.7, 25.9, 15.0. Spectral data match those reported in the literature. 20

3b) 1-butylnaphthalene Purified by FCC using pentane. Yield: 76% (from 1-fluoronaphthtalene), 78% (from 1- chloronaphthalene [>85% GCMS, 9 to 1 mixture with 2-chloronaphthalene], 87 to 13 mixture with 2-isopropylnaphthalene) Molecular Formula: C14H16 1H NMR (300 MHz, CDCl3) δ 8.12-8.06 (m, 1H), 7.88 (dd,J = 8.1, 1.6 Hz, 1H,), 7.74 (d, J = 8.1 Hz, 1H), 7.57-7.47 (m, 2H), 7.43 (dd, J = 8.1, 7.0 Hz, 1H), 7.36 (dd, J = 7.0, 1.3 Hz, 1H), 3.25-2.87 (m, 2H), 1.86- 1.67 (m, 2H), 1.50 (h, J = 7.4 Hz, 2H), 1.01 (t, J = 7.4 Hz, 3H). 13C NMR (75MHz, CDCl3) δ 139.0, 133.9, 131.9, 128.7, 126.4, 125.9, 125.6, 125.5, 125.4, 123.9, 33.0, 32.85, 22.9, 14.1. Spectral data match those reported in the literature. 21

3c) hexylnaphthalene Purified by FCC using pentane. Starting from commercially available 1-chloronaphthalene (>85% GCMS, 9 to 1 mixture with 2-1-chloronaphthalene) Yield: 87% (9 to 1 mixture with 2-hexylnaphthalene) Molecular Formula: C16H20 1H NMR (300 MHz, CDCl3) δ 8.11 (dd, J = 8.3, 1.5 Hz, 0.82H), 7.91 (dd, J = 7.8, 1.8 Hz, 0.9H), 7.88-7.80 (m, 0.34H), 7.76 (d, J = 8.1 Hz, 0.77H), 7.67 (s, 0.10H), 7.60-7.49 (m, 1.78H), 7.49-7.42 (m, 1H), 7.38 (dd, J = 6.9, 1.2 Hz, 0.9H), 3.20-3.04 (m, 2H), 2.90-2.71 (m, 0.27H), 1.88-1.70 (m, 2H), 1.57-1.46 (m, 2H), 1.44-1.30 (m, 4H), 1.07-0.89 (m, 3H). 13C

NMR (75MHz, CDCl3) δ 139.0, 133.9, 131.9, 128.7, 127.9, 127.7, 127.6, 127.4, 127.4, 126.4, 126.3, 125.8, 125.8, 125.6, 125.5, 125.3, 124.9, 123.9, 36.1, 33.1, 31.8, 31.4, 30.8, 29.5, 29.0, 22.7, 14.1. Spectral data match those reported in the literature. 22

20

Z.-J. Shi, J. Am. Chem. Soc., 2008, 130, 3268-3269. 20 21

B. L. Feringa, Nature Chemistry, 2013, 5, 667-672. 22

1-hexylnaphthalene: Z.-J. Shi, Chem. Commun., 2013, 49, 7794-7796

3d) isopropylnaphthalene Purified by FCC using pentane. Starting from commercially available 1-chloronaphthalene (>85% GCMS, 9 to 1 mixture with 2-chloronaphtalene) Yield: 63% (85 to 15 mixture with 2-isopropylnaphthalene) Molecular Formula: C13H14 1H NMR (300 MHz, CDCl3) δ 8.17 (d, J = 8.4 Hz, 0.85H), 7.92-7.86 (m, 1H), 7.86-7.79 (m, 0.3H), 7.77- 7.71 (m, 0.85H), 7.59-7.41 (m, 4H), 3.80 (hept, J = 6.7 Hz, 0.85H), 3.21-3.00 (m, 0.15H), 1.45 (d, J = 6.9 Hz, 5.1H), 1.39 (d, J = 6.9 Hz, 0.9H). 13

C NMR (75MHz, CDCl3) δ 144.6, 133.9, 131.3, 128.9, 127.9, 127.8, 127.6, 126.3, 125.8, 125.8, 125.7, 125.6, 125.6, 125.2, 125.0, 124.1, 123.3, 121.7, 28.5, 23.9, 23.5. Spectral data match those reported in the literature. 23

3e) 2-Ethylanthracene Purified by FCC using pentane. Isolated as a 90:10 mixture with anthracene. Yield: 67% (74% as a 90:10 mixture with anthracene) Molecular Formula: C16H14 1H NMR (300 MHz, CDCl3) δ 8.41 (s, 1H), 8.37 (s, 1H), 8.07-7.99 (m, 2H), 7.97 (d, J = 8.7 Hz, 1H), 7.79 (s, 1H), 7.52-7.44 (m, 2H), 7.38 (dd, J = 8.7, 1.6 Hz, 1H), 2.89 (q, J = 7.6 Hz, 2H), 1.41 (t, J = 7.6 Hz, 3H). 13C NMR (75MHz, CDCl3) δ 141.1, 132.0, 131.8, 131.2, 130.5, 128.2, 128.1, 128.0, 127.3, 125.9, 125.4, 125.2, 124.9, 124.9, 29.2, 15.1. Spectral data match those reported in the literature. 24

3f) 2-hexylanthracene Purified by FCC using pentane. Isolated as an 90:10 mixture with anthracene. Yield: 39% (43% as an 90:10 mixture with anthracene) Molecular Formula: C20H22 1H NMR (300 MHz, CDCl3) δ 8.40 (s, 1H), 8.36 (s, 1H), 8.08-7.98 (m, 2H), 7.96 (d, J = 8.7 Hz, 1H), 7.77 (s, 1H), 7.53-7.42 (m, 2H), 7.36 (dd, J = 8.7, 1.7 Hz, 1H), 2.83 (t, J = 7.7 Hz, 2H), 1.86-1.67 (m, 2H), 1.51-1.25 (m, 6H), 1.00-0.82 (m, 3H). 13C NMR (75MHz, CDCl3) δ 139.8, 132.0, 131.8, 131.2, 130.5, 128.1, 128.0, 128.0, 127.5, 125.9, 125.7, 125.3, 125.2, 124.9, 36.3, 31.8, 31.0, 29.1, 22.6, 14.1. HRMS: Calculated for C20H23O [M+H]+ 263.1794; found 236.1792.

23

For both 1 & 2-isopropylnaphthalene see: B. L. Feringa, Chem. Sci., 2014, 5, 1361-1367. 24

3g) 1-ethylanthracene Purified by FCC using pentane. Contains trace amounts anthracene. Yield: 94% Molecular Formula: C16H14 1H NMR (300 MHz, CDCl3) δ 8.62 (s, 1H), 8.44 (s, 1H), 8.13-7.95 (m, 2H), 7.88 (d, J = 8.4 Hz, 1H), 7.52- 7.31 (m, 4H), 3.27 (q, J = 7.5 Hz, 2H), 1.49 (t, J = 7.5 Hz, 3H). 13C NMR (75MHz, CDCl3) δ 140.1, 132.2, 131.5, 131.3, 130.5, 128.5, 127.9, 126.9, 126.7, 125.3, 125.2, 125.2, 123.7, 122.4, 26.0, 14.7. HRMS: Calculated for C16H15 [M+H]+ 207.1168; found 207.0801.

3h) 1-butylanthracene Purified by FCC using pentane. Isolated as a 95:5 mixture with anthracene 23 Yield: 80% (84% as an 95:15 mixture with anthracene) Molecular Formula: C18H18 1H NMR (300 MHz, CDCl3) δ 8.62 (s, 1H), 8.44 (s, 1H), 8.13-7.95 (m, 2H), 7.89 (d, J = 8.4 Hz, 1H), 7.53, 7.45 (m, 2H), 7.44-7.30 (m, 2H), 3.23 (t, 2H), 2.04-1.78 (m, 2H), 1.64-1.41 (m, 2H), 1.04 (t, J = 7.3 Hz, 3H). 13C NMR (75MHz, CDCl3) δ 138.9, 132.3, 131.5, 131.3, 130.7, 128.6, 127.9, 127.0, 126.8, 125.4, 125.3, 125.2, 124.8, 122.6, 33.1, 32.7, 23.0, 14.1. HRMS: Calculated for C18H19 [M+H]+ 235.1481; found 235.1478.

3i) 1-hexylanthracene Purified by FCC using pentane. Yield: 85% Molecular Formula: C20H22 1H NMR (300 MHz, CDCl3) δ 8.62 (s, 1H), 8.44 (s, 1H), 8.12-7.94 (m, 2H), 7.89 (d, J = 8.4 Hz, 1H), 7.54- 7.44 (m, 2H), 7.44-7.36 (m, 1H), 7.36-7.29 (m, 1H), 3.22 (t, J = 9 Hz, 2H), 1.99-1.78 (m, 2H), 1.63-1.23 (m, 6H), 0.94 (t, J = 6.9 Hz, 3H). 13C NMR (75MHz, CDCl3) δ 138.8, 132.2, 131.5, 131.2, 130.6, 128.5, 127.9, 126.9, 126.7, 125.3, 125.2, 125.1, 124.7, 122.5, 33.3, 31.8, 30.4, 29.6, 22.7, 14.1. HRMS: Calculated for C20H23 [M+H]+ 236.1794; found 236.1791.

3j) 1-isopropylanthracene Purified by FCC using pentane. Isolated as an 69:41 mixture with anthracene Yield: 55% (79% as an 69:41 mixture with anthracene) Molecular Formula: C17H16 1H NMR (300 MHz, CDCl3) δ 8.70 (s, 1H), 8.45 (s, 1H), 8.14-7.95 (m, 2H), 7.88 (d, J = 8.0 Hz, 1H), 7.59- 7.34 (m,

4H), 3.94 (hept, J = 6.9 Hz, 1H), 1.50 (d, J = 6.8 Hz, 6H). 24 13C NMR (75MHz, CDCl3) δ 144.54, 132.33, 131.49, 131.11, 130.03, 128.62, 127.79, 127.03, 126.58, 125.32, 125.20, 125.16, 122.05, 120.84, 28.77, 23.53. HRMS: Calculated for C16H17O [M+H]+ 221.1325; found 221.0956.

3k) 1-cyclopropylanthracene Purified by FCC using pentane. Yield: 66% Molecular Formula: C17H14 1H NMR (300 MHz, CDCl3) δ 8.99 (s, 1H), 8.45 (s, 1H), 8.14- 8.08 (m, 1H), 8.06-7.99 (m, 1H), 7.89 (d, J = 8.5 Hz, 1H), 7.55-7.46 (m, 2H), 7.39 (dd, J = 8.5, 6.8 Hz, 1H), 7.32-7.21 (m, 1H), 2.62-2.36 (m, 1H), 1.20-1.13 (m, 2H), 0.89-0.81 (m, 2H). 13C NMR (75MHz, CDCl3) δ 139.3, 132.1, 132.1, 131.7, 131.5, 128.8, 128.1, 127.0, 126.9, 125.5, 125.4, 125.2, 123.2, 123.0, 13.7, 6.5.