Mechanistic insights into the iridium-catalyzed hydrosilylation of allyl compounds

Progress on Iridium-Catalyzed Hydrosilylation of Alkenes and Alkynes

“…Kühn's group first conducted mechanistic studies on the iridium-catalyzed hydrosilylation of allyl compounds in 2015. 26 As shown in Scheme 13, their experimental data supports the proposal of different initial steps for two types of allylic substrate. In the presence of allyl ethyl ether, [(COD)IrCl] 2 prefers to initially undergo oxidative addition with the hydrosilane to generate the iridium(III) intermediate A, which then coordinates with the olefin to form intermediate E. In comparison, allyl chloride is suggested to initially react with [(COD)IrCl] 2 to form allylic intermediate B, which could be converted into monomeric iridium(I) intermediate C by consuming two molecules of the hydrosilane.…”

Iridium-Catalyzed Hydrosilylation of Unactivated Alkenes: Scope and Application to Late-Stage Functionalization

“…Generation of intermediate Ir­(I) hydride A (in Scheme , b) is presumptively crucial in this process, which we envisioned is probably one key factor in other iridium-catalyzed hydrosilylation processes as well. , Meanwhile, the existence of heteroatoms or functional groups that can coordinate to the iridium center might facilitate these catalytic conversions. Herein, we demonstrate our research on the Ir-catalyzed hydrosilylation of unactivated alkenes with excellent anti -Markovnikov regioselectivity and high efficiency, which provides complementary examples and additional insight into previous reports. − , This catalytic system is suitable for a broad substrate scope, especially for those containing heteroatoms. More importantly, it works effectively on late-stage hydrosilylation, which is rarely reported before.…”

“…Surprisingly, despite usually recognized as one main kind of precious metal catalysts in alkene hydrosilylation, reports on exploitation of iridium complexes for this process are rare. Till now, most of the related works were published as patents, which mainly focused on simple terminal alkenes. , Inspired by this research vacancy, a few works were released recently. − Shimada reported the iridium-catalyzed hydrosilylation of allyl acetates and sulfur-containing olefins . Kühn gave a mechanistic study on the iridium-catalyzed hydrosilylation of allyl compounds .…”

“…Till now, most of the related works were published as patents, which mainly focused on simple terminal alkenes. , Inspired by this research vacancy, a few works were released recently. − Shimada reported the iridium-catalyzed hydrosilylation of allyl acetates and sulfur-containing olefins . Kühn gave a mechanistic study on the iridium-catalyzed hydrosilylation of allyl compounds . Recently, one of us, together with Sun and Wu, developed iridium-catalyzed hydrosilylation of internal thioalkynes with excellent regio- and stereoselectivity .…”

Iridium-Catalyzed Hydrosilylation of Sulfur-Containing Olefins

“…Thus, the hydrosilylation of allyl phenyl sulfide 5a with (MeO) 3 SiH, 4a , was catalyzed by 2 to form the hydrosilylated product 6a in 86% yield at the catalyst loading of 4 mol % (Table , entry 1). Since 2 is easily converted to 1 on the treatment of (MeO) 3 SiH, 4a , hydrosilylation reactions catalyzed either 1 or 2 are likely to proceed following the same reaction mechanism.…”