General Allylic C–H Alkylation with Tertiary Nucleophiles
作者:Jennifer M. Howell、Wei Liu、Andrew J. Young、M. Christina White
DOI:10.1021/ja500726e
日期:2014.4.16
A general method for intermolecular allylic C–H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C–H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins
Instead of undergoing a cyclopentenone annulation, the allylmalonate anion derived from the dicarboxylate (7) rearranges to vinylsuccinate (5), an application of which has led to a convenient synthesis of vinylnaphthoquinones (10).
Meldrum's acids can be allylated by allylic alcohols usingtetrakis[triphenylphosphine]palladium(0) [(PPh 3 ) 4 Pd] as a catalyst in benzene at 80°C without prior activation of allylic hydroxy group.