BINAP/AgOTf/KF/18-crown-6 as new bifunctional catalysts for asymmetric Sakurai-Hosomi allylation and Mukaiyama aldol reaction.
A catalytic amount of KF.18-crown-6 complex is effective as a soluble fluoride source to activate an asymmetric Sakurai-Hosomi allylation with BINAP and silver(I) triflate catalyst. The allylation of a variety of aromatic, alpha,beta-unsaturated and aliphatic aldehydes with allylic trimethoxysilane resulted in high yields and remarkable enantioselectivities. In addition, the asymmetric Mukaiyama-type aldol reaction is achieved by using trimethoxysilyl enol ethers in the presence of the same catalysts. High anti selectivity is obtained from E-silyl enol ether, while Z-silyl enol ether gives syn selectivity.
Wadamoto
Manabu
M
Graduate School of Engineering, Nagoya University, SORST, Japan Science and Technology Corporation (JST), Chikusa, Nagoya 464-8603, Japan.
Ozasa
Nobuko
N
Yanagisawa
Akira
A
Yamamoto
Hisashi
H