Asymmetric reduction of 2-(N-arylimino)-3,3,3-trifluoropropanoic acid esters leading to enantiomerically enriched 3,3,3-trifluoroalanine
作者:Takashi Sakai、Fengyang Yan、Setsuo Kashino、Kenji Uneyama
DOI:10.1016/0040-4020(95)00866-7
日期:1996.1
2-(N-arylimino)-3,3,3-trifluoropropanoic acid esters with a chiral oxazaborolidine catalyst and subsequent oxidative removal of N-aromatic moiety with retention of the configuration. Detailed optimization studies revealed that the effects of solvents, temperature, and the structural modification of the substrate were drastic on the enantioselectivity. The absolute configuration of 1 was determined to be (R) by
对映体富集的3,3,3-三氟丙氨酸(1)(高达62%ee)已通过手性恶唑硼烷催化剂和2-(N-芳基氨基)-3,3,3-三氟丙酸酯的不对称还原和随后氧化除去N-芳族部分并保留构型。详细的优化研究表明,溶剂,温度和底物的结构改性对对映选择性的影响很大。通过相应的N-(S)-(+)-樟脑磺酰基衍生物的X射线晶体学分析确定1的绝对构型为(R)。