Wadamoto Manabu, Ozasa Nobuko, Yanagisawa Akira, Yamamoto Hisashi
Graduate School of Engineering, Nagoya University, SORST, Japan Science and Technology Corporation (JST), Chikusa, Nagoya 464-8603, Japan.
J Org Chem. 2003 Jul 11;68(14):5593-601. doi: 10.1021/jo020691c.
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.
催化量的KF·18-冠-6配合物作为一种可溶性氟源,可有效地与联萘酚磷酸酯(BINAP)和三氟甲磺酸银(I)催化剂一起活化不对称樱井-细见烯丙基化反应。各种芳香醛、α,β-不饱和醛和脂肪醛与烯丙基三甲氧基硅烷的烯丙基化反应均能得到高产率和显著的对映选择性。此外,在相同催化剂存在下,使用三甲氧基硅基烯醇醚可实现不对称向山式羟醛缩合反应。从E-硅基烯醇醚可获得高反式选择性,而Z-硅基烯醇醚则给出顺式选择性。