Synthesis and reactions of t-butyltellurocarbonyloxyalkanes
作者:Anthony G. M. Barrett、Derek H. R. Barton、Roger W. Read
DOI:10.1039/c39790000645
日期:——
Reaction of t-butyl(chloromethylene)dimethyl-ammonium chloride with alcohols and sodium hydrogen telluride gave t-butyltellurocarbonyloxyalkanes; 3β-t-butyltellurocarbonyloxy-5α-cholestane [ButC(=Te)OR] with diphenylseleninic anhydride and sodium hydrogen telluride gave, respectively, esters (ButCO2R) and ethers (ButCH2OR) and [(ButCHOR)2].
conventional methodologies. The boosted nucleophilicity resulting from the constrained tetracoordinated calix[4]pyrrolato stannate(II) dianion enables the reductive formation of sterically unprotected acyclic aminocarbenes. These amino carbenes are stabilized at the concomitantly formed square-planar stannane(IV) as air-stable adducts. Transfer of the carbenes onto copper(I) by cooperativity of the
近年来,结构约束方法已被用于不同的目的,从增强金字塔化低价 p 区化合物的亲核性到增强平面化四价 p 区元素的路易斯酸性。虽然之前的研究分别利用了这些效应,但这项工作引入了一种策略,可以在连续反应序列的各个阶段串联结构约束方法,以解锁传统方法无法实现的合成路径。受约束的四配位杯[4]吡咯锡酸(II)二价阴离子导致亲核性增强,能够还原形成空间未受保护的无环氨基卡宾。这些氨基卡宾以空气稳定的加合物形式稳定在同时形成的方形平面锡烷(IV) 上。通过杯[4]吡咯配体的协同作用将卡宾转移到铜(I)上,最终形成迄今为止尚未报道的原型卡宾配合物。详细的光谱和量子理论分析确立了结构约束和元素-配体合作的协同作用,作为该反应路径及其选择性的关键。
Oszczapowicz, Janusz; Ciszkowski, Konrad, Journal of the Chemical Society. Perkin transactions II, 1987, p. 663 - 668
作者:Oszczapowicz, Janusz、Ciszkowski, Konrad
DOI:——
日期:——
A Simple Route to Unsymmetrically Substituted 1,2,4,5-Tetrazines
作者:Stephen C. Fields、Marshall H. Parker、W. Randal Erickson
DOI:10.1021/jo00105a059
日期:1994.12
Neue Dialkylamino-allene, -thiophene und -pyrrole aus Vinamidinium-Salzen