A novel 1,2-migration of arylzincates bearing a leaving group at benzylic position: Application to a three-component coupling of p-iodobenzyl derivatives, trialkylzincates, and electrophiles leading to functionalized p-substituted benzenes
作者:Toshiro Harada、Takayuki Kaneko、Takayuki Fujiwara、Akira Oku
DOI:10.1016/s0040-4020(98)00569-9
日期:1998.8
p-iodobenzyl methanesulfonate to give benzylzinc reagents p-RC6H4CH2Zn(L). The reaction proceeds through a mechanism involving initial iodine/zinc exchange and the 1,2-migration of the resulting arylzincates. The benzylzinc reagents, thus prepared, are subsequently used in coupling reaction with electrophiles such as aldehydes, ketones, acyl chlorides, tosyl cyanide, and chlorosilanes to give a variety of functionalized
描述了对碘苄基衍生物,三烷基锌酸酯和亲电试剂的三组分偶联。三烷基锌酸锂(R 3 ZnLi)与对碘苄基甲烷磺酸酯反应,得到苄基锌试剂对-RC 6 H 4 CH 2 Zn(L)。该反应通过涉及初始碘/锌交换和所得芳基锌酸酯的1,2-迁移的机理进行。如此制得的苄锌试剂随后用于与亲电子试剂如醛,酮,酰氯,甲苯磺酰氰和氯硅烷的偶合反应,得到各种官能化的p取代的苯。在Barbier条件下的反应,其中在亲电子试剂的存在下生成相应的苄基锌试剂,对于Me 3 ZnLi和衍生自Grignard试剂的锌酸镁R 3 ZnMgBr效果很好。从二乙基1-(对碘苯基)乙基磷酸酯开始的仲苄基锌试剂的产生以及它们与亲电试剂的反应也在巴比尔条件下实现。在这些条件下,酮,烯丙基溴和氯硅烷已成功用作亲电子试剂。