Regioselectivity-Switchable Hydroarylation of Styrenes
作者:Ke Gao、Naohiko Yoshikai
DOI:10.1021/ja108809u
日期:2011.1.26
Cobalt-phosphine and cobalt-carbene catalysts have been developed for the hydroarylation of styrenes via chelation-assisted C-H bond activation, to afford branched and linear addition products, respectively, in a highly regioselective fashion. Deuterium-labeling experiments suggested a mechanism involving reversible C-H bond cleavage and olefin insertion steps and reductive elimination as the rate-
chelates are readily obtained upon coordination of metal species to multidentate ligands. Because of the robust structural nature, chelation frequently serves as a drivingforce in the molecular assembly and chemical architecture, and they are used also as an efficientcatalyst in numerous reactions. Described herein is the development of a Rh(NHC) catalytic system for the hydroarylation of alkenes and alkynes
Rhodium-catalysed regioselective alkylation of the phenyl ring of 2-phenylpyridines with olefins
作者:Yeong-Gweon Lim、Yong Hae Kim、Jung-Bu Kang
DOI:10.1039/c39940002267
日期:——
2-Phenylpyridines react with olefins react with olefins in the presence of rhodium(I) as a catalyst to give 2-(2-alkylphenyl)pyridines by a regioselective alkylation at the ortho position of the phenyl ring.
Regioselective alkylation of 2-phenylpyridines with terminal alkenes via C–H bond activation by a rhodium catalyst
作者:Yeong-Gweon Lim、Jung-Bu Kang、Yong Hae Kim
DOI:10.1039/p19960002201
日期:——
2-Phenylpyridine 1a reacts with various terminal alkenes in the presence of a rhodium(I) complex catalyst to give the corresponding mono ortho-alkylated products 2a-i and doubly alkylated products 3a-b (9:1), The same reaction using 3-methyl-2-phenylpyridine 1b gives the mono alkylated products 2j-n exclusively under the same reaction conditions due to steric hindrance between the methyl group of the pyridine and the alkyl group of 2j-n.
Lim Yeong-Gweon, Kim Yong Hae, Kang Jung-Bu, J. Chem. Soc. Chem. Commun, (1994) N 19, S 2267-2268