One-pot conversion of activated alcohols into 1,1-dibromoalkenes and terminal alkynes using tandem oxidation processes with manganese dioxide
作者:Ernesto Quesada、Steven A. Raw、Mark Reid、Estelle Roman、Richard J.K. Taylor
DOI:10.1016/j.tet.2005.12.077
日期:2006.7
Approaches to the preparation of C1-homologated dibromoalkenes and terminal alkynes from activated alcohols using one-pot tandem oxidation processes (TOPs) with manganesedioxide are outlined. The conversion of alcohols into dibromoalkenes is described using dibromomethyltriphenylphosphonium bromide and the formation of terminal alkynes was achieved via a sequential one-pot, two-step process utilising
for the preparation of 3-substituted isocoumarins via palladium-catalyzed nucleophilic addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective nucleophilic addition and C–H functionalization procedure.
RuCl3·3H2O Catalyzed Tandem Reaction of Alkynylbromides with 2-Aminothiophenols in Water: A Convenient Synthesis of 2-Benzoylbenzothiazoles
作者:Xuesen Fan、Yan He、Shenghai Guo、Xinying Zhang
DOI:10.1071/ch11217
日期:——
RuCl3·3H2Ocatalyzedtandemreaction of alkynyl bromides with 2-aminothiophenols mediated by water is shown to represent a convenient synthesis of 2-benzoylbenzothiazoles. In addition, the Ru(iii) catalyst could be readily recovered and efficiently reused together with water up to three times.
Dioxazoles, a new mild nitrene transfer reagent in gold catalysis: highly efficient synthesis of functionalized oxazoles
作者:Ming Chen、Ning Sun、Haoyi Chen、Yuanhong Liu
DOI:10.1039/c6cc02776h
日期:——
A gold-catalyzed regioselective [3+2] cycloaddition of ynamides with 1,4,2-dioxazoles has been developed, which offers a novel approach to highly functionalized oxazoles under mild reaction conditions. 1,4,2-Dioxazole was found to act...
A regio‐ and stereoselective method for the preparation of (Z)‐vinyl thiocyanate derivatives by silver‐catalyzed thiocyanation of haloalkynes is reported. This method features practical, free of ligand, broad substrate scope, excellent stereoselectivity and gram‐scale synthesis. Significantly, the halogen atom of haloalkynes is retained, which allows the synthesis of 2,5‐diphenylthiophene, thiazol‐2‐amine