作者:Masanori Takimoto、Yoichi Nakamura、Kaoru Kimura、Miwako Mori
DOI:10.1021/ja049506y
日期:2004.5.1
A method for nickel-catalyzed asymmetric carbondioxide (CO2) incorporation via carbon-carbon bond formation was developed. In the presence of a catalytic amount of Ni(acac)2 and MeO-MOP, various bis-1,3-dienes reacted with CO2 (1 atm) and a diorganozinc reagent (Me2Zn or Ph2Zn) to afford cyclic carboxylicacids in good yields (71-100%) and with high enantioselectivities (90-96% ee).
Nickel-Catalyzed Enantioselective Three-Component Coupling of Bis-1,3-dienes, Aldehydes, and Dimethylzinc
作者:Masanori Takimoto、Yuuki Kajima、Yoshihiro Sato、Miwako Mori
DOI:10.1021/jo051283m
日期:2005.10.1
bis-1,3-dienes, aldehyde, and dimethylzinc was investigated. In the presence of catalytic amounts of Ni(acac)2 and PPh3, bis-1,3-dienes smoothly react with an aldehyde and dimethylzinc via intramolecular cyclodimerization of bis-1,3-diene moiety. The reaction proceeds through formation of a cyclic bis-allylnickel complex, insertion of an aldehyde, and addition of dimethylzinc to the resulting oxanickellacycle
Pd(0) catalyst promotes three-component coupling reactions of allylic alcohols and vinylcyclopropanes with terminal alkynes and triethylborane to provide (E)-1-substituted 2-ethyl-1,4-pentadienes and (E)-1-substituted 2-ethyl-1,4-heptadienes involving geminal ethylation and allylation at the acetylenic terminal carbon atom with high regio- and stereoselectivities. 1,3-Butadiene and bis-dienes can act as allylating agents to undergo the multi-component coupling reactions, accompanied by dimerization of the diene moieties, to provide 1,4,9-decatrienes and pyrrolidines with excellent regio- and stereoselectivities.