At the Forefront of the Suzuki–Miyaura Reaction: Advances in Stereoselective Cross-Couplings

Quaternary Ammonium Salts as Alkylating Reagents in C–H Activation Chemistry

“…Selective C–C bond-forming reactions are very fundamental and often-used reactions in organic chemistry, since they are key to building the skeletons of any organic compound. Among the plethora of reported C–C bond forming reactions, metal-catalyzed transformations have gained significant prominence, initially, due to the Nobel prize-winning chemistry of cross-coupling reactions, and, more recently, due to transition-metal-catalyzed C–H activation reactions, which can be considered as the logical advancement of cross-coupling reactions. These reactions generally eliminate the need for at least one prefunctionalized substrate by replacing it with a C–H bond, giving rise to more step- and atom-efficient transformations.…”

The dioxasilepanyl group as a versatile organometallic unit: studies on stability, reactivity, and utility

“…Rare examples of “tough and switchable” Ms that meet these criteria are known to be suited for modular syntheses of complex molecules. In the case of organoboron functional groups, 2 the B(pin) (pinacolatoboryl) group has almost monopolized this need in modern organic synthesis since this cyclic dialkoxyborane shows moderate stability during purifications on silica gel, while having a boron centre with a vacant p-orbital that is easily activated for various transformations. Because of this contradictory nature, neither stability nor reactivity is perfect.…”

Recent Advances in Metal-Catalyzed Alkyl–Boron (C(sp3)–C(sp2)) Suzuki-Miyaura Cross-Couplings

“…In line, the intensive research in metal catalysis has led to significant progress in borylation of primary C(sp 3 )-H bonds of unfunctionalized hydrocarbons, allowing access to a variety of C(sp 3 )-B reagents and consequent breakthroughs in C(sp 3 )-C(sp,sp 2 ,sp 3 ) cross-couplings. Comprehensive work has been done on the development of an efficient sp 2 −sp 2 SMC; however, there have been far fewer reports on sp 3 −sp 2 or sp 3 −sp 3 variants [31][32][33][34][35][36][37][38]. Among the different hybridized boron reagents employed in SMCs (e.g., aryl, heteroaryl, and vinylboronic acids and esters), the use of organoboron compounds with alkyl groups (sp 3 carbon) was severely limited in these coupling reactions due to competitive side reactions [39,40].…”