18510-28-6Relevant articles and documents
Cobalt-Catalyzed Regiodivergent Hydrosilylation of Vinylarenes and Aliphatic Alkenes: Ligand- and Silane-Dependent Regioselectivities
Wang, Chao,Teo, Wei Jie,Ge, Shaozhong
, p. 855 - 863 (2017)
We report a regiodivergent hydrosilylation of alkenes catalyzed by catalysts generated in situ from bench-stable Co(acac)2 and phosphine- or nitrogen-based ligands. A wide range of vinylarenes and aliphatic alkenes reacted to afford either branched (45 examples) or linear (37 examples) organosilanes in high isolated yields (average: 84%) and high regioselectivities (from 91:9 to >99:1). This transformation tolerates a variety of functional groups including ether, silyloxy, thioether, epoxide, halogen, amine, ester, boronic ester, acetal, cyano, and ketone moieties. Mechanistic studies suggested that the hydrosilylation of alkenes catalyzed by the cobalt/bisphosphine system follows the Chalk-Harrod mechanism (with a Co-H intermediate), and the hydrosilylation of alkenes catalyzed by the cobalt/pyridine-2,6-diimine system follows the modified Chalk-Harrod mechanism (with a Co-Si intermediate). Systematic studies with sterically varied silanes revealed that the steric properties of silanes play a pivotal role in controlling the regioselectivity of vinylarene hydrosilylation and the chemoselectivity of the reactions of aliphatic alkenes and silanes catalyzed by the cobalt/pyridine-2,6-diimine system.
Nickel-Catalyzed Hydrosilylation of Terminal Alkenes with Primary Silanes via Electrophilic Silicon-Hydrogen Bond Activation
Wu, Xiaoyu,Ding, Guangni,Lu, Wenkui,Yang, Liqun,Wang, Jingyang,Zhang, Yuxuan,Xie, Xiaomin,Zhang, Zhaoguo
supporting information, p. 1434 - 1439 (2021/02/16)
We report a simple and effective nickel-based catalytic system, NiCl2·6H2O/tBuOK, for the electrophilically activated hydrosilylation of terminal alkenes with primary silanes. This protocol provides excellent performance under mild reaction conditions: ex
Base-Metal-Catalyzed Regiodivergent Alkene Hydrosilylations
Du, Xiaoyong,Zhang, Yanlu,Peng, Dongjie,Huang, Zheng
supporting information, p. 6671 - 6675 (2016/06/08)
A complementary set of base metal catalysts has been developed for regiodivergent alkene hydrosilylations: iron complexes of phosphine-iminopyridine are selective for anti-Markovnikov hydrosilylations (linear/branched up to >99:1), while the cobalt complexes bearing the same type of ligands provide an unprecedented high level of Markovnikov selectivity (branched/linear up to >99:1). Both systems exhibit high efficiency and wide functional group tolerance. Regiodivergent alkene hydrosilylation has been accomplished with high efficiency using a newly developed set of complementary base metal catalyst systems. An inversion of regioselectivity (linear/branched) from >99:1 to 1:99 is obtained when the iron version of the catalyst is exchanged for a cobalt-containing analogue.
