Design of Brønsted Acid-Assisted Chiral Brønsted Acid Catalyst Bearing a Bis(triflyl)methyl Group for a Mannich-Type Reaction
作者:Aiko Hasegawa、Yuki Naganawa、Makoto Fushimi、Kazuaki Ishihara、Hisashi Yamamoto
DOI:10.1021/ol060939a
日期:2006.7.1
[Structure: see text] A new Bronsted acid-assisted chiral Bronsted (chiral BBA) acid catalyst (1) was developed by substituting a hydroxy group of optically active 1,1'-bi(2-naphthol) with a stronger Bronsted acidic group such as a bis(trifluoromethanesulfonyl)methyl group. The enantioselective Mannich-type reaction of ketene silyl acetals with aldimines catalyzed by (R)-1 in the presence of stoichiometric
[结构:见正文]通过用强布朗斯台德酸性基团取代旋光1,1'-bi(2-萘酚)的羟基,开发了一种新的布朗斯台德酸辅助手性布朗斯台德(手性BBA)酸催化剂(1)。如双(三氟甲磺酰基)甲基。在化学计量的非手性质子源的存在下,烯酮甲硅烷基乙缩醛与由(R)-1催化的醛亚胺的对映选择性曼尼希型反应高产率地得到(S)-β-氨基酯,对映体过量至中度。