作者:Mariusz Bosiak、Marcin Pakulski
DOI:10.1055/s-0030-1258355
日期:2011.1
The catalytic asymmetric reduction of α-keto aldoxime O-methyl, O-benzyl, and O-trityl ethers, derived from substituted acetophenones, with borane/oxazaborolidines, by transfer hydrogenation, and with yeast, was studied. The reduction with borane/oxazaborolidines produced the corresponding α-hydroxy oxime ethers, α-hydroxy hydroxylamine ethers, and β-amino alcohols in 39-78% yields and up to 77% ee. The carbonyl group was selectively reduced by transfer hydrogenation with formic acid-triethylamine catalyzed by RhCl[(R,R)-TsDPEN](C5Me5), and also with yeast, producing α-hydroxy oxime ethers, up to 75% ee and 93% ee, respectively.
研究了硼烷/噁唑硼烷通过转移加氢和酵母催化不对称还原从取代苯乙酮衍生的 O-甲基、O-苄基和 O-三苯甲基δ酮醛肟醚的过程。用硼烷/噁唑硼烷还原产生了相应的δ-羟基肟醚、δ-羟基羟胺醚和δ-氨基醇,产率为 39-78%,ee高达 77%。在 RhCl[(R,R)-TsDPEN](C5Me5)催化下,羰基通过甲酸-三乙胺转移加氢选择性地还原,也可通过酵母还原,生成δ-羟基肟醚,ee值分别高达 75% 和 93%。