Synthesis of Unsymmetrical 1,4-Dicarbonyl Compounds by Photocatalytic Oxidative Radical Additions
作者:Ya Dong、Ruining Li、Junliang Zhou、Zhankui Sun
DOI:10.1021/acs.orglett.1c02208
日期:2021.8.20
Herein we report a photocatalytic oxidative radical addition reaction for the synthesis of unsymmetrical 1,4-dicarbonyl compounds. This reaction utilizes a desulfurization process to generate electrophilic radicals, which add to α-halogenated alkenes and undergo further oxidation to deliver 1,4-dicarbonyl compounds. This mild and highly efficient method provides a valuable alternative to known strategies
Two highly reactive iodoalkenes (1-iodo-1-(2-naphthyl)ethene and 1-iodo-1-(1-naphthyl)ethene) were prepared from the corresponding acetonaphthone isomers via their hydrazones and used as substrates in palladium-catalysed carbonylations. Both iodoalkenyl substrates proved to be highly reactive in the presence of various N-nucleophiles and the corresponding N-substituted naphthylacrylamides were formed chemoselectively in nearly quantitative yields. High isolated yields (up to 93%) were achieved with all types of amines under mild reaction conditions. The alkoxycarbonylation of the above iodoalkenes resulted in esters of unexpectedly good isolated yields (up to 77%). (C) 2009 Elsevier Ltd. All rights reserved.
Atom-Efficient Vinylic Arylations with Triarylbismuths as Substoichiometric Multicoupling Reagents under Palladium Catalysis
作者:Maddali L. N. Rao、Deepak N. Jadhav、Varadhachari Venkatesh
Here we describe a ruthenium-catalyzed regioselective hydrohalogenation reaction of alkynes under mild conditions. Commercially simple halogen sources such as KI, ZnBr2, and ZnCl2 were employed to achieve this transformation. Alkynes derived from bioactive molecules such as l-(−)-borneol, l-menthol, and estrone were also suitable for the transformation, demonstrating the potential synthetic value of