Asymmetric construction of quaternary carbons from chiral malonates : Total syntheses of (+)-epilaurene and (−)-Isolaurene.
摘要:
Enantiomerically pure (+)-epilaurene and (-)-isolaurene were obtained from the chiral malonic acid ester (R)-(+)-4, via the 4-methyl-4-p-tolylhex-5-en-1-al (S)-9 prepared by double Wittig reaction under sonication, which underwent subsequent radical induced cyclization.
Asymmetric construction of quaternary carbons from chiral malonates : Total syntheses of (+)-epilaurene and (−)-Isolaurene.
摘要:
Enantiomerically pure (+)-epilaurene and (-)-isolaurene were obtained from the chiral malonic acid ester (R)-(+)-4, via the 4-methyl-4-p-tolylhex-5-en-1-al (S)-9 prepared by double Wittig reaction under sonication, which underwent subsequent radical induced cyclization.
centers is a marked challenge in asymmetric catalysis research. It is extremely difficult when a chiral catalyst can not distinguish the facial selectivity of the substrate through bond interactions. Here we realized an enantioselective Michaelreaction of silyl ketene imines to 1-acrylpyrazoles using a chiral N,N′-dioxide–Co(II) complex. The protocol is highly efficient for the construction of nitrile-