Tris(2,4,6‐trifluorophenyl)borane: An Efficient Hydroboration Catalyst

Lawson, James R.; Wilkins, Lewis C.; Melen, Rebecca L.

doi:10.1002/chem.201703109

Cited by 114 publications

(59 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All these procedures require more or less effective catalysts based on transition-metal complexes such as Co, Fe, Ru, [15][16][17][18][19][20][21][22][23] alkaline earth metal (Mg), [24][25][26][27][28][29][30][31][32][33][34][35] but the processes culminate in frustrated Lewis pairs. [36][37][38] On the other hand, while the reduction of aryl and alkyl nitriles can be achieved using stoichiometric quantities of maingroup reducing agents such as LiAlH 4 and NaBH 4 , [39] the combustible nature of these reagents and large quantities of inorganic waste by-products they generate render the process unattractive, and hence reductive hydroboration is preferable in order to provide further functionality to the resultant amine. [40] Recently, Nakazawa et al reported the use of an ironindium complex as a catalyst for the hydroboration of aryl and alkyl nitriles, [41] while Nikonov et al introduced the Mo(IV) complex as a catalyst (5 mol %), which resulted in the hydroboration of acetonitrile and benzonitrile using the only catecholborane.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Hydroboration of Organic Nitriles Promoted by Aluminum Complex

2018

View full text Add to dashboard Cite

We demonstrate an efficient protocol for the chemoselective hydroboration of organic nitriles with pinacolborane (HBpin) and catecholborane (HBcat) using aluminum alkyl complex [k 2 -{2-FÀC 6 H 4 NP(Se)Ph 2 } 2 AlÀ(Me)] as a pre-catalyst to afford diboryl amines under solvent-free and mild conditions (60 8C) in high yield. The aluminum complex was prepared by the reaction of [2-FÀC 6 H 4 NHP(Se)Ph 2 ] and trimethylaluminum in toluene. The solid-state structure of Al complex is established. Nitriles with a wide array of electronwithdrawing and electron-donating functional groups were easily converted to the desired products through the formation of aluminum hydride as an active species. A kinetic study of the catalytic reaction is also reported.

show abstract

Section: Introductionmentioning

confidence: 99%

Catalytic Hydroboration of Organic Nitriles Promoted by Aluminum Complex

2018

View full text Add to dashboard Cite

show abstract

“…2‐(4‐Fluorobenzyloxy)pinacolborane (1f): 1 H NMR (600 MHz, C 6 D 6 ): δ = 7.10–7.04 (m, 2H), 6.80–6.73 (m, 2H), 4.79 (s, 2H), 1.04 (s, 12H). 13 C{ 1 H} NMR (151 MHz, C 6 D 6 ): δ = 162.6 (d, 1 J CF = 244.6 Hz), 135.8 (d, 4 J CF = 3.3 Hz), 128.9 (d, 3 J CF = 8.0 Hz), 115.3 (d, 2 J CF = 21.4 Hz), 82.8, 66.2, 24.7.…”

Section: Methodsmentioning

confidence: 99%

“…2‐(2‐Bromobenzyloxy)pinacolborane (1i): 1 H NMR (600 MHz, C 6 D 6 ): δ = 7.54 (d, 3 J HH = 7.5 Hz, 1H), 7.26 (d, 3 J HH = 7.5 Hz, 1H), 6.96 (t, 3 J HH = 7.5 Hz, 1H), 6.70 (t, 3 J HH = 7.5 Hz, 1H), 5.09 (s, 2H), 1.04 (s, 12H). 13 C{ 1 H} NMR (151 MHz, C 6 D 6 ): δ = 139.0, 132.5, 128.8, 128.0, 127.6, 121.8, 83.0, 66.6, 24.7.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Nickel(II) Catalyzed Hydroboration: A Route to Selective Reduction of Aldehydes and N‐Allylimines

Hossain

Schmidt

2020

Eur J Inorg Chem

View full text Add to dashboard Cite

A cationic [(iminophosphine)nickel(allyl)] + complex was found to be sufficiently electrophilic to activate aldehydes and N-allylimines to undergo hydroboration with pinacolborane (HBpin) under mild reaction conditions. The catalyst displayed excellent selectivity toward aldehydes in the presence of ketones. A wide variety of functional groups were tolerated, includ- [a] I. 1877 ing halogens, NO 2 , CN, OMe, and alkenes for both aldehydes and imines. Electron-rich substrates were found to be significantly more reactive than their electron poor counterparts, a feature that was correlated to their enhanced ability to coordinate to the Lewis acidic nickel center. [40] Colorless liquid (60 mg, 81 % isolated yield). 1 H NMR (600 MHz, CDCl 3 ): δ = 7. 33-7.30 (m, 4H), 7.25-7.22 (m, 1H), 5.92 (ddt, 3 J HH = 17.2, 3 J HH = 10.2, 3 J HH = 6.0 Hz, 1H), 5.19 (dq, 3 J HH = 17.2, 4 J HH = 2 J HH = 1.5 Hz, 1H), 5.10 (dq, 3 J HH = 10.2, 4 J HH = 2 J HH = 1.5 Hz, 1H), 3.78 (s, 2H), 3.27 (dt, 3 J HH = 6.0, 4 J HH = 1.5 Hz, 2H), 1.47 (br s, 1H). 13 C{ 1 H} NMR (151 MHz, CDCl 3 ): δ = 140. 3, 136.9, 128.5, 128.3, 127.1, 116.1, 53.4, 51.9. [30a] Colorless liquid (74 mg, 92 % isolated yield). 1 H NMR (600 MHz, CDCl 3 ): δ = 7.22 (d, 3 J HH = 7.9 Hz, 2H), 7.15 (d, 3 J HH = 7.9 Hz, 2H), 5.94 (ddt, 3 J HH = 17.2, 3 J HH = 10.2, 3 J HH = 6.0 Hz, 1H), 5.20 (dq, 3 J HH = 17.2, 4 J HH = 2 J HH = 1.6 Hz, 1H), 5.12 (dq, 3 J HH = 10.2, 4 J HH = 2 J HH = 1.6 Hz, 1H), 3.76 (s, 2H), 3.28 (dt, 3 J HH = 6.0, 4 J HH = 1.6 Hz, 2H), 2.35 (s, 3H), 1.52 (br s, [41] Colorless liquid (81 mg, 91 % isolated yield). 1 H NMR (600 MHz, CDCl 3 ): δ = 7.24 (d, 3 J HH = 8.3 Hz, 2H), 6.86 (d, 3 J HH = 8.3 Hz, 2H), 5.93 (ddt, 3 J HH = 17.3, 3 J HH = 10.4, 3 J HH = 6.0 Hz, 1H), 5.19 (dq, 3 J HH = 17.3, 4 J HH = 2 J HH = 1.6 Hz, 1H), 5.11 (dq, 3 J HH = 10.4, 4 J HH = 2 J HH = 1.6 Hz, 1H), 3.79 (s, 3H), 3.73 (s, 2H), 3.26 (dt, 3 J HH = 6.0, 4 J HH = 1.6 Hz, 2H), 1.45 (br s, 1H). 13 C{ 1 H} NMR (151 MHz, CDCl 3 ): δ = 158. 7, 136.9, 132.5, 129.5, 116.1, 113.8, 55.4, 52.8, 51.8. N-Benzylprop-2-en-1-amine (2b): N-(4-Methylbenzyl)prop-2-en-1-amine (2c): N-(4-Methoxybenzyl)prop-2-en-1-amine (2d): N-(4-N,N-Dimethylaminobenzyl)prop-2-en-1-amine(2e): [30a] Pale yellow liquid (87 mg, 91 % isolated yield). 1 H NMR (600 MHz, CDCl 3 ): δ = 7.20 (d, 3 J HH = 8.6 Hz, 2H), 6.72 (d, 3 J HH = 8.6 Hz, 2H), 5.94 (ddt, 3 J HH = 16.8, 3 J HH = 10.1, 3 J HH = 6.1 Hz, 1H), 5.19 (dq, 3 J HH = 16.8, 4 J HH = 2 J HH = 1.6 Hz, 1H), 5.10 (dq, 3 J HH = 10.1, 4 J HH = 2 J HH = 1.6 Hz, 1H), 3.70 (s, 2H), 3.27 (dt, 3 J HH = 6.1, 4 J HH = 1.6 Hz, 2H), 2.94 (s, 6H), 1.38 (br s, 1H). 13 C{ 1 H} NMR (151 MHz, CDCl 3 ): δ = 149.9, 136.9, 129.2, 128.2, 115.9, 112.7, 52.8, 51.7, 40.8. N-(4-Fluorobenzyl)prop-2-en-1-amine (2f):[30a] Colorless liquid (71 mg, 86 % isolated yield). 1 H NMR (600 MHz, CDCl 3 ): δ = 7.32-7.27 (m, 2H), 7.04-6.98 (m, 2H), 5.92 (ddt, 3 J HH = 17.1, 3 J HH = 10.2, 3 J HH = 5.9 Hz, 1H), 5.19 (dq, 3 J HH = 17.1, 4 J HH = 2 J HH = 1.4 Hz, 1H), 5.12 (dq, 3 J HH = 10.2, 4 J HH = 2...

show abstract

“…[1][2][3] Classically, there has been focus on the use of precious metal catalysts for this transformation, [4][5][6] but recently there has been a surge of interest in using more abundant, non-toxic, and cheaper alternatives such as early transition metals and main group elements. 1,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Recent work has shown that Lewis acidic boranes and borocations can act as efficient catalysts for this process (Fig. 1).…”

mentioning

confidence: 99%