光学活性N,N-二烷基-β-氨基醇硼烷配合物对酮的不对称还原反应

Asymmetric Reduction of Ketones Using Optically Active N, N-Dialkyl-β-Aminoalcohol-Borane Complexes

从天然氨基酸出发制得的九种新的光学活性N,N-二烷基-β-氨基醇,分别与硼烷反应生成相应的手性(口恶)唑硼烷配合物并将其用于不对称还原反应中。硼烷-手性(口恶)唑硼烷-还原体系能将脂肪酮和芳香酮还原为仲醇,化学还原收率町达100％,光学收率也比较高。并简单讨论了立体效应,反应温度和溶剂效应对此还原反应的影响。

Nine new optically active N, N-dialkyl-β-aminoalcohols synthesized from natural amino acids reacted with borane in THF to give chiral oxazoborolidines. The borane modified by chiral oxazoborolidines enantioselectively reduced aliphatic and aromatic ketones to yield sec-alcohols with 100% yield and medium to high optical yields. Some influences of steric effect, reaction temperature and solvent effects were discussed.