Catalytic asymmetric aldol reactions. Use of a chiral (acyloxy)borane complex as a versatile Lewis-acid catalyst
作者:Kyoji Furuta、Tohru Maruyama、Hisashi Yamamoto
DOI:10.1021/ja00003a047
日期:1991.1
In the presence of 20 mol% of a chiral (acyloxy)borane (CAB) complex prepared from (2R,3R)-2-O(2,6-diisopropoxybenzoyl)tartaric acid and borane-tetrahydrofuran, various allyltrimethylsilanes react with achiral aldehydes to afford the corresponding homoallylic alcohols in good yields with high diastereo- and enantioselectivities. Furthermore, the reactivity of allylation can be improved without reducing
在由 (2R,3R)-2-O(2,6-二异丙氧基苯甲酰基) 酒石酸和硼烷-四氢呋喃制备的 20 mol% 手性(酰氧基)硼烷 (CAB) 配合物存在下,各种烯丙基三甲基硅烷与非手性醛反应生成以良好的收率提供相应的高烯丙醇,具有高非对映选择性和对映选择性。此外,3,5-双(三氟甲基)苯基硼酸和手性酒石酸衍生物制备的CAB配合物占10-20mol%,可以在不降低对映选择性的情况下提高烯丙基化反应的反应活性。观察到的选择性和亲核试剂对醛的羰基碳的重新攻击意味着扩展的过渡态模型是适用的