Selective synthesis of (Z)-2-enynyl-2-hydroxy-imidazolidine-4,5-diones via Cu(<scp>i</scp>)-mediated multicomponent coupling of terminal alkynes, carbodiimides and oxalyl chloride
作者:Fei Zhao、Yuexing Li、Yang Wang、Wen-Xiong Zhang、Zhenfeng Xi
DOI:10.1039/c4ob00185k
日期:——
(Z)-2-Enynyl-2-hydroxy-imidazolidine-4,5-diones 2 are synthesized for the first time via Cu(I)-mediated (Z)-selective geminal coupling among two molecules of terminal alkynes, carbodiimides, and oxalylchloride. Further transformation of 2a is performed to yield a highly functionalized spiro heterocyclic compound 5.
Metal-free synthesis of cyclic di-oxoguanidines via one-pot sequential transformation of amines, carbodiimides and acyl dichlorides
作者:Fei Zhao、Yang Wang、Wen-Xiong Zhang、Zhenfeng Xi
DOI:10.1039/c2ob25799h
日期:——
The one-pot sequential reaction of various amines, carbodiimides, and acyl dichlorides has been achieved for the first time under metal-free conditions to provide symmetric cyclic di-oxoguanidines via an unexpected 2,2-dichloro-imidazolidindione intermediate. Acyl dichlorides have a dual function: to serve as the third component and to activate carbodiimides. In sharp contrast, the AlMe3-catalyzed sequential reaction from the same substrates gives the isomer.
A novel protocol for the activation of the Beckmannrearrangement utilizing the readily available and economical geminal dichloroimidazolidinediones (DCIDs) on a substoichiometric scale (10 mol %) has been developed. A unique self-propagating mechanism for the substoichiometric dichloroimidazolidinedione-activated transformation was proposed and validated. The substrate scope of the developed protocol
Reductive generation of stable, five-membered N,N′-diamidocarbenes
作者:Jonathan P. Moerdyk、Christopher W. Bielawski
DOI:10.1039/c4cc00846d
日期:——
The synthesis of the first stable, five-membered N,Nâ²-diamidocarbenes (DACs), including a differentially N-substituted derivative, was achieved via the reduction of a geminal dichloride precursor using potassium. Key differences between the reactivity of the five-membered DACs and their six-membered congeners were observed, including an ability to insert into electron-rich CâH bonds.