Hydrozirconation of Stannylacetylenes. Synthesis and Reactions of Ketene Stannyl(Telluro) Acetals
作者:Miguel J. Dabdoub、Adriano C. M. Baroni
DOI:10.1021/jo991015m
日期:2000.1.1
ketene stannyl(seleno) acetals 12. Otherwise, the use of 1.4 equiv of Cp(2)Zr(H)Cl and 1.0 equiv of PhSeBr results in the exclusive formation of 12, in good yields. Treatment of ketene stannyl(telluro) acetals with iodine or NBS followed by reductive dehalogenation results in the formation of 1-iodo-1-telluroalkenes 4a-e and 1-bromo-1-telluroalkenes 5a-e, respectively, with total retention of the configuration
室温下,苯乙烯基乙炔7a-e与Cp(2)Zr(H)Cl在THF中反应,生成α-锆化乙烯基锡烷中间体8a-e,随后与丁基碲烯基溴化物(2.0当量)反应,仅生成烯基苯乙烯基(碲) E构型的乙缩醛6a-e。使用苯基硒烯基溴化物(2.0当量)作为亲电子试剂进行了类似的反应,但形成了包括预期的乙烯酮苯乙烯基(硒基)缩醛12在内的产物混合物。否则,使用1.4当量的Cp(2)Zr(H)Cl和1.0当量的PhSeBr可以排他地形成12,收率很好。用碘或NBS处理乙烯酮苯乙烯基(telluro)乙缩醛,然后进行还原性脱卤作用,分别形成1-碘-1-碲代烯烃4a-e和1-溴-1-碲代烯烃5a-e,并完全保留组态。