Novel chiral dibenzo[a,c]cycloheptadiene bis(oxazoline) and catalytic enantioselective cyclopropanation of styrene
作者:Da-Ming Du、Bin Fu、Wen-Ting Hua
DOI:10.1016/s0040-4020(03)00144-3
日期:2003.3
A series of chiral C2-symmetric bis(oxazoline) ligands containing dibenzo[a,c]cycloheptadiene units were synthesized. The copper complexes, prepared in situ from copper (I)-triflate and the new enantiopure oxazoline ligands, were assessed as chiral catalysts in the enantioselective cyclopropanation of styrene with diazoacetate. Enantioselectivities up to 82 and 62%, respectively, for trans- and ci
合成了一系列含有二苯并[ a,c ]环庚二烯单元的手性C 2对称双(恶唑啉)配体。由三氟甲磺酸铜(I)和新的对映体纯的恶唑啉配体原位制备的铜配合物在苯乙烯与重氮乙酸酯的对映选择性环丙烷化中被评估为手性催化剂。观察到反式和苯基-2-苯基环丙烷羧酸酯的对映选择性分别高达82%和62%。