Silylations of Arenes with Hydrosilanes: From Transition‐Metal‐Catalyzed CX Bond Cleavage to Environmentally Benign Transition‐Metal‐Free CH Bond Activation

Abstract

The construction of carbon-silicon bonds is highlighted as an exciting achievement in the field of organosilicon chemistry and green chemistry. Recent developments in this area will enable the sustainable chemical conversion of silicon resources into synthetically useful compounds. Especially, the catalytic silylation through C¢H bond activation without directing groups and hydrogen acceptors is one of the most challenging topics in organic chemistry and green chemistry. These remarkable findings on catalytic silylation can pave the way to a more environmentally benign utilization of earth-abundant silicon-based resources in synthetic chemistry.

Recent Advances in Transition-Metal-Catalyzed Silylations of Arenes with Hydrosilanes: C–X Bond Cleavage or C–H Bond Activation­ Synchronized with Si–H Bond Activation

“…The reaction was conducted with 1,1,3,3,5,5,5-heptamethyltrisiloxane (7), a hydrosilane possessing two sterically demanding trimethylsilyloxy (TMSO) substituents, as the silicon source and arenes as limiting reagents in the presence of cyclohexene as a hydrogen acceptor. Various symmetric and unsymmetric 1,3-disubstituted and 1,2-disubstituted arenes (8)(9)(10)(11)(12) were silylated with high regioselectivity (Scheme 4). 13 In addition, the silylation of indole derivative 13 and benzofuran 14 occurred at the 2-position of the heteroarene with ≥97:3 selectivities.…”

“…The two types of catalytic Si-C coupling reactions mentioned above have been covered partially in several excellent reviews, from different aspects. [1][2][3][4][5][6][7][8][9][10] Very recently, Sharma's group published a review on selective C-Si bond formation via functionalization of both sp 3 and sp 2 C-H bonds. 10 However, no comprehensive review with special focus on the catalytic synthesis of different arylsilanes and the characteristics of transition-metal-based catalyst systems is available to date.…”

The mechanism of oxidative addition of Pd(0) to Si–H bonds: electronic effects, reaction mechanism, and hydrosilylation

“…1c), [65][66][67] C-Si cross-coupling reactions (Fig. 1d), 68,69 and hydrodehalogenation reactions (Fig. 1e), [70][71][72][73][74][75] amongst others.…”

Mechanistic Insights into Palladium‐Catalyzed Silylation of Aryl Iodides with Hydrosilanes through a DFT Study

“…Catalytic selective silylation of aryl halides is an atom‐economic and alternative approach to classic Si−C coupling reaction with a Grignard reagent and chlorosilanes to obtain aryl silanes . Among the versatile developed synthetic methods, palladium‐catalyzed silicon–carbon cross‐coupling through dehalogenative coupling of aryl halide (Scheme ) with hydrosilane has attracted much attention, owing to its superior functional group comparability and improved atom economy.…”