One-Pot Synthesis of Optically Active Cyanohydrin Acetates from Aldehydes via Quinidine-Catalyzed Transhydrocyanation Coupled with Lipase-Catalyzed Kinetic Resolution in Organic Solvent
作者:Minoru Inagaki、Akihiko Hatanaka、Mitsuo Mimura、Jun Hiratake、Takaaki Nishioka、Jun’ichi Oda
DOI:10.1246/bcsj.65.111
日期:1992.1
transhydrocyanation allows for in situ racemization of the unreacted cyanohydrins and concurrent kinetic resolution by lipase enabled the preparation of (S)-3b–d with 40–82% e.e. in more than 50% yield. Polymer-supported cinchona alkaloid was also used as a catalyst for this one-pot reaction and showed the comparable chemical and optical yield to that for the soluble monomeric alkaloid. The insoluble polymer and lipase
开发了一种新的一锅合成方法来制备旋光氰醇乙酸酯。通过奎尼丁催化的氢氰化反应从醛和丙酮氰醇中生成外消旋氰醇,然后使用乙酸异丙烯酯作为酰化剂,通过脂肪酶以立体选择性方式将所得氰醇 2a-j 乙酰化。多种醛 1a-j 成功地转化为相应的氰醇乙酸酯 3a-j,其 ee 为 47-95%,而没有分离不稳定的氰醇 2。此外,碱催化转移氢氰化的可逆性质允许未反应的氰醇原位外消旋化脂肪酶同时进行动力学拆分使 (S)-3b-d 能够以 50% 以上的产率制备 40-82% ee 的 (S)-3b-d。聚合物负载的金鸡纳生物碱也被用作这种一锅反应的催化剂,并显示出与可溶性单体生物碱相当的化学和光学产率。不溶性聚合物和脂肪酶...