Hydrosilylation and hydroboration in a sustainable manner: from Earth-abundant catalysts to catalyst-free solutions

Abstract

Hydroelementation enables a facile reduction or functionalization of several unsaturated systems, and thus activation of such bonds like B–H and Si–H is a powerful synthetic tool.

Hydroelementation of diynes

“…The process initiates from the insertion of diyne 1a-d or 27a-c into the Ru-H bond of catalyst 28 forming but-3-en-1-yn-3-yl complex 32. The addition of borane 25 then leads to a s-bond metathesis between Ru-C and B-H (33), followed by the elimination of the product 29 and regeneration of the initial Ru-hydride complex 28 (Scheme 8 and Fig. 1).…”

“…Hydroelementation reactions are one of the most prominent transformations in organic and organometallic chemistry, to obtain functionalised compounds from the addition of E-H bonds (E = Mg, B, Al, Si, Ge, Sn, N, P, O, S, Se, Te) to unsaturated C-C bonds in olefins (CQC) or alkynes (CRC), C-N bonds in imines (CQN) 2,[32][33][34][35][36] or nitriles (CRN), 2,33,34,37 and CQO bonds in carbonyl compounds. 2,[32][33][34][35][38][39][40][41][42][43][44][45][46][47] The processes are mostly catalytic but may also occur as uncatalysed. In both cases, the stereo-and regioselectivity of the reaction depends upon the catalyst, reagent, and reaction conditions.…”

Aluminium complexes: next-generation catalysts for selective hydroboration

“…Amongst various methods used to synthetically prepare useful organoboranes, one of the most fundamental methods is the hydroboration of any unsaturated C–X bonds. 1–12 The first example of hydroboration is the pioneering work by Brown et al where a H–B bond was added to an alkene in an anti -Markovnikov fashion (Scheme 1a). 13–15 The most straightforward hydroboration reagent involves the use of diborane ((BH 3 ) 2 ) or an adduct formed with THF (BH 3 ·THF) or alkyl borane (Scheme 1b).…”

Cationic Zinc Hydride Catalyzed Carbon Dioxide Reduction to Formate: Deciphering Elementary Reactions, Isolation of Intermediates, and Computational Investigations

“…[1][2][3][4] They are employedi nt he reduction of olefins, [5][6][7][8] imines, [9][10][11] aldehydes, ketones, [12][13][14][15][16][17][18] and carbond ioxide. [19][20][21][22][23][24][25][26][27][28][29][30] Catalyticr eductiono f carbon dioxide through catalytic hydrosilylation [31][32][33][34] and, to some extent, hydroboration [35,36] with zinc catalysts has been investigated. [37][38][39][40][41][42][43][44] Zinc acetate is known to hydrosilylateC O 2 to am ixture of reduced products:s ilyl formates, bis(silyl) acetals, methoxysilanes, and methane.…”