Syntheses of Substituted 1,4-Disila-2,5-cyclohexadienes from Cyclic Hexasilane Si<sub>6</sub>Me<sub>12</sub> and Alkynes via Successive Si–Si Bond Activation by Pd/Isocyanide Catalysts
作者:Atsushi Tahara、Shunsuke Nagino、Yusuke Sunada、Ryohei Haige、Hideo Nagashima
DOI:10.1021/acs.organomet.8b00302
日期:2018.8.13
Palladium-catalyzed reactions of dodecamethylcyclohexasilane [(SiMe2)6] (1) with alkynes led to efficient preparation of 1,1,4,4-tetramethyl-1,4-disilacyclohexadienes (3). The reactions were best catalyzed by Pd(0) species generated from Pd2(dba)3·CHCl3 and 1-isocyanoadamantane (AdNC). Terminal and internal alkynes bearing aryl and alkyl substituents could be used as substrates, and the reaction allowed
十二甲基环己硅烷[(SiMe 2)6 ](1)与炔烃的钯催化反应可有效制备1,1,4,4-四甲基-1,4-二硅环己二烯(3)。反应最好由Pd 2(dba)3 ·CHCl 3和1-异氰基金刚烷(AdNC)生成的Pd(0)物种催化。带有芳基和烷基取代基的末端和内部炔烃可以用作底物,并且该反应允许克级制备3。甲二甲基亚甲硅基(ME 2的Si :)物种,通过在Si-Si键的激活产生1由Pd(0)物种引起,参与了反应机理。在DFT计算表明,氧化加成的Si-Si键在1到的Pd(CNAD)2种之后是我的挤出2 Si═Pd(CNAD)中间体。所得的钯配位的甲硅烷基与炔烃的反应形成硅杂环丙烯,其二聚化得到3。挤出伴随有1的环收缩以生成(SiMe 2)5,其还通过与炔烃的Pd(0)催化的反应而有助于形成3和(SiMe 2)4。挤出我2Si═Pd(CNAd)和环收缩从(SiMe 2)6(1)生成了五种以上的Me