作者:Herbert C. Brown、Ashok K. Gupta
DOI:10.1016/0022-328x(88)89064-8
日期:1988.3
synthesis of boron heterocycles from borinic and boronic esters with α-amino acids was explored as a means of upgrading the optical purities of intermediates from asymmetric hydroboration. B-Methoxy-9-borabicyclo[3.3.1]nonane, methyl dicyclohexylborinate and (+)- and (-)-methyl diisopinocampheylborinate react with various α-amino acids to form the corresponding crystalline chelates. Recrystallization
探索了由硼酸酯和硼酸酯与α-氨基酸合成硼杂环的方法,该方法可提高非对称氢硼化中间体的光学纯度。B-甲氧基-9-硼环[3.3.1]壬烷,二环己基硼酸甲酯和(+)-和(-)-甲基二异樟脑基硼酸酯与各种α-氨基酸反应形成相应的结晶螯合物。从甲基产生的螯合物的重结晶的反式-2- phenylcyclopentylisopinocampheylborinate 85%ee的与升-苯丙氨酸,甲基isopinocampheyl-外-norbornylborinate用83%ee的的升-脯氨酸,并用92%ee的的甲基diisopinocampheylborinate的两个光学异构体升-脯氨酸可产生相应的光学纯度接近100%ee的产品。在用亚氨基二乙酸和N-甲基亚氨基二乙酸处理后,环戊基硼酸二甲酯,外-降冰片基硼酸二甲酯和异-异樟脑基硼酸二甲酯形成相应的双环硼酸酯。衍生自3-四氢吡喃基硼酸二乙酯和亚氨基二乙