Enantioselective Ring Opening of Epoxides with Cyanide Catalysed by Halohydrin Dehalogenases: A New Approach to Non-Racemic β-Hydroxy Nitriles
作者:Maja Majerić Elenkov、Bernhard Hauer、Dick B. Janssen
DOI:10.1002/adsc.200505333
日期:2006.3
Halohydrin dehalogenases (HheA, HheB and HheC) were found to efficiently catalyse a carbon-carbon bond forming reaction between terminal aliphatic epoxides and cyanide, yielding β-hydroxy nitriles. With all three enzymes nucleophilic ring opening of epoxides proceeds with high regioselectivity to the β-carbon atom. Activity, enantioselectivity and enantiopreference depend on the type of enzyme and
发现卤代醇脱卤素酶(HheA,HheB和HheC)可有效催化末端脂肪族环氧化物与氰化物之间的碳-碳键形成反应,生成β-羟基腈。通过所有这三种酶,环氧化物的亲核开环以对β-碳原子的高区域选择性进行。活性,对映选择性和对映选择性取决于酶的类型和底物结构。发现HheC在测试的酶中具有最高的选择性。对单取代环氧化物的对映选择性从中等到高(E = 5–106)变化,而2,2-二取代环氧化物的拆分以非常高的对映选择性(E= 141和200)。结果表明,卤代醇脱卤酶可能成为从外消旋环氧化物容易地制备对映纯β-羟基腈的有吸引力的催化剂。