<i>Cine</i>-Substitution in the Stille Coupling: Evidence for the Carbenoid Reactivity of sp<sup>3</sup>-<i>g</i><i>em</i>-Organodimetallic Iodopalladio-trialkylstannylalkane Intermediates
作者:Eric Fillion、Nicholas J. Taylor
DOI:10.1021/ja037409j
日期:2003.10.1
been proposed as Pd-carbenoid precursors in the Busacca-Farina cine-substitution mechanism in the Stille coupling. The decomposition of iodomethyltrialkylstannanes by Pd(0) catalysts was monitored by 1H, 2D, and 119Sn NMR. The formation of ethylene, trace formaldehyde, and iodotrialkylstannanes was detected. When the reaction was carried out in the presence of norbornene, the corresponding cyclopropane
介绍了 sp3-gem-organodimetaliodopalladio-trialkylstannanylalkanes 的两条互补路线。在 Stille 耦合中的 Busacca-Farina 电影取代机制中,此类中间体已被提议为 Pd-carbenoid 前体。Pd(0) 催化剂对碘甲基三烷基锡烷的分解由 1H、2D 和 119Sn NMR 监测。检测到乙烯、痕量甲醛和碘代三烷基锡烷的形成。当反应在降冰片烯存在下进行时,相应的环丙烷收率良好。这些观察结果与 Pd-carbenoid 物种的中间性一致。sp3-gem-有机二金属碘钯-三烷基锡烷基烷烃配合物也在化学计量条件下通过从锡到 Pd(II) 的金属转移制备。Me3SnCH2Sn(CH2CH2CH2)3 与 [(Dt-BPF)PdI]+I- 反应,产生 (Dt-BPF)Pd(II)ICH2SnMe3 复合物,该复合物二聚形成乙烯