has recently been generated from hypervalent iodine precursors via photoredox catalysis. Given the underexplored chemistry of carbyne, due to the paucity of carbyne sources, we are intrigued to discover a new source for this reactive species from classical reagents – phosphonium ylides. Our novel strategy employing phosphonium ylides in an olefin hydrocarbonation reaction features a facile approach
with coppercomplexes as catalysts. The reactions involve iminyl-radical-mediated intramolecular hydrogen atom transfer as the key step, with the iminyl radicals being generated via copper-effected N–O cleavage. The reaction afforded 3,4-dihydro-2H-pyrroles under the conditions of [Cu(DPEphos)(bcp)]PF6 and DABCO, while γ-pentafluorobenzoyloxy ketones were produced predominantly when [Cu(dpp)2]PF6 and
The nickel-catalyzed three-component reductive carbonylation of alkylhalides, aryl halides, and ethyl chloroformate is described. The use of ethyl chloroformate as a safe and readily available source of CO provides an efficient and practical alternative for the synthesis of aryl-alkyl ketones.
描述了烷基卤化物、芳基卤化物和氯甲酸乙酯的镍催化三组分还原羰基化。使用氯甲酸乙酯作为一种安全且容易获得的 CO 来源,为芳基烷基酮的合成提供了一种有效且实用的替代方案。
Ti-Catalyzed Modular Ketone Synthesis from Carboxylic Derivatives and <i>gem</i>-Dihaloalkanes
作者:Jiabin Ni、Xiaowen Xia、Danyu Gu、Zhaobin Wang
DOI:10.1021/jacs.3c04009
日期:2023.7.12
Ketones are ubiquitous in organic synthesis. However, the general method to convert widely available carboxylic acids, unactivated esters, and amides into ketones remains elusive. Herein, we describe the Ti-catalyzed modular ketonesynthesisfrom carboxylic derivatives and easily accessed gem-dihaloalkanes. Notably, this protocol could achieve the direct catalytic olefination of carboxylic acids. This
A binap-ligated copper dimer has been heterogenized on a pillar-layered MOF surface for the first time using a hydroxamic acid linker. This MOF-supported dimeric copper photocatalyst demonstrates much higher activity and recyclability than its homogeneous counterparts in intra- and intermolecular radicalreactions of N-acyloxy imidates and O-acyl oximes.