Transition-Metal-Catalyzed Silylation and Borylation of C–H Bonds for the Synthesis and Functionalization of Complex Molecules

Abstract

The functionalization of C−H bonds in organic molecules containing functional groups has been one of the holy grails of catalysis. One synthetically important approach to the diverse functionalization of C−H bonds is the catalytic silylation or borylation of C−H bonds, which enables a broad array of downstream transformations to afford diverse structures. Advances in both undirected and directed methods for the transition-metal-catalyzed silylation and borylation of C−H bonds have led to their rapid adoption in early-, mid-, and late-stage of the synthesis of complex molecules. In this Review, we review the application of the transition-metal-catalyzed silylation and borylation of C−H bonds to the synthesis of bioactive molecules, organic materials, and ligands. Overall, we aim to provide a picture of the state of art of the silylation and borylation of C−H bonds as applied to the synthesis and modification of diverse architectures that will spur further application and development of these reactions.

Aryl Chloride-Directed Enantioselective C(sp2)-H Borylation Enabled by Iridium Catalysis

“…Therefore, an FG with even extremely low a could be a competent DG. , In this regard, the Sawamura group reported an elegant example of Ar–Cl directed ortho -C­( sp 2 )-H borylation using SMAP-Ir­(OMe)­(cod) catalysis (Scheme B) . Inspired by this presence, we envisioned that Ar–Cl-directed asymmetric C­(sp 2 )-H borylation of arenes should be a viable approach in the presence of a proper chiral iridium catalyst . In the past few years, our group has developed Ir-catalyzed asymmetric C–H borylation enabled by chiral bidentate boryl ligands ( CBL s). , More recently, CBL /Ir catalysis was found to be effective in simple ether-directed asymmetric C–H borylation. , The low a of ethers encouraged us to further investigate Ar–Cl as the DG in asymmetric C–H borylation.…”

Catalytic Enantioselective Primary C–H Borylation for Acyclic All-Carbon Quaternary Stereocenters

“…To this end, many efforts involving substrates with prefunctionalized reactive sites have been devoted, , including polar strategies, , one-electron processes, and rearrangement reactions . On the other hand, transition metal-catalyzed asymmetric C–H activation protocol for these motifs is still at the infancy stage compared with constructing other chiral units . Yu and co-workers pioneered an elegant work on amide-directed Pd-catalyzed enantioselective C–H activation of gem -dimethyl groups .…”

C–H borylation: a tool for molecular diversification

“…22 Pioneering groups like those of Gaunt (synthesis of rhazinicine: 2008), 29 Sarpong (synthesis of (+)-complanadine A: 2010), 30 and Baran (synthesis of verruculogen and fumitremorgin A: 2015) 31 used C–H functionalization and borylation techniques as the key steps towards the total synthesis of complex natural products. 32 Considering all these examples, undoubtedly, it may be stated that nowadays this strategy has evolved to be one of the mainstream techniques used to synthesize natural products, pharmaceutical ingredients, and organic materials.…”