Optically active 1-(benzofuran-2-yl)ethanols and ethane-1,2-diols by enantiotopic selective bioreductions
摘要:
Enantiotopic selective reduction of 1-(benzofuran-2-yl)ethanones 1a-d, 1-(benzofuran-2-yl)-2-hydroxyethanones 4a-c and 2-acetoxy-1-(benzofuran-2-yl)ethanones 3a-c was performed by baker's yeast for preparation of optically active (benzofuran-2-yl)carbinols [(S)-5a-d, (S)-6a-c and (R)-6a-c, enantiomeric excess from 55 to 93% ee]. (C) 2003 Elsevier Science Ltd. All rights reserved.
Asymmetric synthesis of benzofuryl β-amino alcohols by the transfer hydrogenation of α-functionalized ketones
作者:Agnieszka Tafelska-Kaczmarek、Marek P. Krzemiński、Marta Ćwiklińska
DOI:10.1016/j.tet.2017.05.059
日期:2017.7
The asymmetrictransferhydrogenation of representative benzofuryl α-sulfonyloxy ketones and N-protected α-amino ketones with an azeotropic mixture of formic acid/triethylamine, catalyzed by RhCl[(R,R)-TsDPEN](C5Me5), afforded the corresponding 1,2-diol monosulfonates and N-substituted β-amino alcohols in high yields and with enantioselectivities up to 99%. Transformation of the reduction products
用RhCl [(R,R)-TsDPEN](C 5 Me 5)催化的甲酸/三乙胺共沸混合物将代表性的苯并呋喃基α-磺酰氧基酮和N-保护的α-氨基酮进行不对称转移氢化,得到了相应的1,2-二醇单磺酸盐和N-取代的β-氨基醇,收率高,对映选择性高达99%。还描述了还原产物向具有伯胺基的手性苯并呋喃基β-氨基醇的转化。