An efficient synthesis of substituted quinazolin-4(3H)-ones by a one-pot ligand-free CuI-catalyzed coupling/condensative cyclization under mild conditions is described. Our study provides an alternative strategy for the preparation of biologically active quinazolin-4(3H)-ones.
Electrochemical oxidative 5-exo-dig-oxo-halocyclization of o-alkynylbenzamides was achieved using readily available NaX (X = Cl, Br and I) salts under mild reactionconditions. The use of a cheap and highly stable sodiumhalide as a halide ion source is impressive for the synthesis of a variety of halogenated isobenzofuran-1-imines. This electrochemical protocol shows regioselectivity and excellent
during the reaction. Mechanistic studies revealed that the key to the success of this reaction is the generation of a diboron-bridged five-membered ring as a transition state, in which the diboron-bridged five-membered ring and the benzene ring in the transition state are perpendicular to each other, owing to steric repulsion by the iodine atom at the ortho position. This chemoselectivity is suitable for
Visible-Light-Enabled Catalytic Approach to <i>N</i>,<i>O</i>-Spirocycles through Amidyl Radical Addition/Cyclization
作者:Zhihui Liang、Yushen Yu、Lele Zhang、Guotao Xue、Min Liu、Yirui Zhang、Mingqiang Huang、Lina Cai、Shunyou Cai
DOI:10.1021/acs.orglett.3c03855
日期:2024.1.12
A rational combination of photoredox catalyst anthraquinone and hydrogen atom transfer (HAT) catalyst methyl thioglycolate allows for the rapid and straightforward conversion of a range of 2-amidated acetylenic alcohols to multifunctional N,O-spirocycles under visible light irradiation. With oxygen as the sole terminal oxidant, these reactions can be carried out efficiently at room temperature without
Synthesis of <i>N</i>-substituted phthalimides <i>via</i> Pd-catalyzed [4+1] cycloaddition reaction
作者:Chengxian Hu、Lu Wang、Yuanyuan Wu、Yonglong Zheng、Ying Fu、Zhengyin Du
DOI:10.1039/d3cc04534j
日期:——
A novel Pd-catalyzed assembly of N-phenylphthalimide by merging of [4+1] cycloaddition and difluorocarbene transfer carbonylation from 2-iodo-N-phenylbenzamides and difluorocarbene precursors is disclosed. In this reaction, difluorocarbene acts as a carbonyl source and simultaneously forms one C-C bond, one C-N bond and one C=O bond to produce N-phenylphthalimides in high yields.