Cobalt-Catalyzed Regiodivergent Hydrosilylation of Vinylarenes and Aliphatic Alkenes: Ligand- and Silane-Dependent Regioselectivities
作者:Chao Wang、Wei Jie Teo、Shaozhong Ge
DOI:10.1021/acscatal.6b02518
日期:2017.1.6
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
Alkyl Grignard reagents were found to be isomerized to more stable ones in high isomerization ratios (>99%) under cooperative catalysis by iron and copper, which promote isomerization of alkyl groups and transmetalation between Fe-Mg, respectively.
Iron-copper cooperative catalysis is shown to be effective for an alkene-Grignard exchange reaction and alkylmagnesiation of alkynes. The Grignard exchange between terminal alkenes (RCH═CH(2)) and cyclopentylmagnesium bromide was catalyzed by FeCl(3) (2.5 mol %) and CuBr (5 mol %) in combination with PBu(3) (10 mol %) to give RCH(2)CH(2)MgBr in high yields. 1-Alkyl Grignardreagents add to alkynes in the
Synthesis and Characterization of Alkyllanthanum Biphenolate Complexes as Catalysts for Hydroamination/Cyclization and Hydrosilylation
作者:Denis V. Gribkov、Frank Hampel、Kai C. Hultzsch
DOI:10.1002/ejic.200400265
日期:2004.10
phenolate groups of the biphenolate ligands. The two different phenolate groups undergo an intramolecular exchange process in solution leading to their equivalence on the NMR timescale. The biphenolate alkyl complex shows high catalytic activity for hydroamination/cyclization of aminoalkenes, similar to previously known lanthanocene catalysts, but only low enantioselectivity. Addition of THF to [La(R)-Biphen}CH(SiMe3)2}]2
Olefin Hydrosilylation Catalysts Based on Allyl Bis(phenolato) Complexes of the Early Lanthanides
作者:Elise Abinet、Thomas P. Spaniol、Jun Okuda
DOI:10.1002/asia.201000598
日期:2011.2.1
Non‐metallocene allylcomplexes of earlylanthanides (lanthanum, cerium, neodymium, and samarium), that contain a sulfur‐linked bis(phenolate) ligand, catalyze the regioselective hydrosilylation of styrene.