Asymmetric aldol reaction of 2-cyanopropionates catalyzed by a trans-chelating chiral diphosphine–rhodium(I) complex: highly enantioselective construction of quaternary chiral carbon centers at α-positions of nitriles
作者:Ryoichi Kuwano、Hiroshi Miyazaki、Yoshihiko Ito*
DOI:10.1016/s0022-328x(00)00049-8
日期:2000.5
The aldol reaction of 2-cyanopropionates with aldehydes proceeded under neutral conditions in the presence of a catalytic amount of the rhodium complex generated in situ from Rh(acac)(CO)2 and triphenylphosphine, to give the corresponding β-hydroxy-α-cyanocarboxylates bearing a quaternary chiral carbon center at the α-position of the cyano group. A high degree of asymmetric induction for the aldol reaction
2-氰基丙酸酯与醛的醛醇缩合反应在中性条件下,在催化量的Rh(acac)(CO)2和三苯基膦原位生成的铑配合物的存在下进行,得到相应的β-羟基-α-氰基羧酸盐在氰基的α-位带有一个四级手性碳中心。通过使用反式螯合手性二膦配体,(R,R)-2,2″-双[(S)-1-(二芳基膦基)乙基] -1,1实现了高度的醛醇缩合不对称诱导。''-二茂铁(TRAPs)。不对称的醛醇缩合反应得到具有高达94%ee的旋光性β-羟基-α-氰基羧酸盐。