Silylformylation catalyzed by Rh and Rh-Co mixed metal complexes and its application to the synthesis of pyrrolizidine alkaloids
作者:Iwao Ojima、Robert J. Donovan、Masakatsu Eguchi、William R. Shay、Patrizia Ingallina、Anna Korda、Qingping Zeng
DOI:10.1016/s0040-4020(01)87260-4
日期:1993.1
dialkyne, and an alkynyl nitrile proceed in high yields in which alkene and nitrile functionalities are inert for the reaction. Silylformylation is successfully applied to the syntheses of pyrrolizidine alkaloids, (±)-isoretronecanol and (±)-trachelanthamidine, from 5-ethynyl-2-pyrrolidinone (6) in combination with amidocarbonylation.
Co 2 Rh 2(CO)12,Rh 4(CO)12,(t BuNC)4 RhCo(CO)4和Rh(acac)(CO)2在25°C和在大气压至一氧化碳的10个大气压下,得到(Z)-1-甲硅烷基-2-甲酰基-1-己烯(1),这是“甲硅烷基甲酰化”的产物,和/或(E)-1-甲硅烷基-1-己烯(2)。甲硅烷基甲酰化与氢化硅烷化产物的比例取决于所用氢化硅烷的电子性质,例如,PhMe 2 SiH几乎只给出1,而(MeO)3SiH赞成2的形成。当使用三烷基硅烷如Et 3 SiH和EtMe 2 SiH时,由Co 2 Rh 2(CO)12或(t BuNC)4 RhCo(CO)4催化的反应得到2,5-双(正丁基)-3 -甲硅烷基环戊-2-烯-1-酮(3)作为主要产物,是独特的甲硅烷基碳环化产物。形成机理3在氘标记实验的基础上进行了讨论。炔烃,二炔和炔基腈的化学选择性甲硅烷基甲酰化以高收率进行,其中烯烃和腈官