First Cobalt(I)-Catalyzed [6 + 2] Cycloadditions of Cycloheptatriene with Alkynes
作者:Mathieu Achard、Alphonse Tenaglia、Gérard Buono
DOI:10.1021/ol050618j
日期:2005.6.1
CoI2(dppe)/Zn/ZnI2 system effectively catalyzes the [6 + 2] cycloaddition of cycloheptatriene with terminal alkynes to afford 7-alkyl-bicyclo[4.2.1]nona-2,4,7-trienes in fair to excellent yields. The catalyst proved to be tolerant toward functional groups such as ketone, sulfone, ester, ketal, ether, alcohol, imide, and nitrile. The enantioselective cycloaddition of CHT and phenylacetylene with BINOL phosphoramidite
[反应:参见文本] CoI2(dppe)/ Zn / ZnI2系统有效地催化环庚三烯与末端炔烃的[6 + 2]环加成反应,得到7-烷基-双环[4.2.1] nona-2,4,7-三烯的收率中等至优异。事实证明该催化剂对酮,砜,酯,缩酮,醚,醇,酰亚胺和腈等官能团具有耐受性。CHT和苯乙炔与BINOL亚磷酰胺配体4的对映选择性环加成得到环加合物3a(R = Ph),产率为91%,ee为74%。