O-Acetyl Oximes as Transformable Directing Groups for Pd-Catalyzed C−H Bond Functionalization
摘要:
O-Acetyl oximes serve as effective directing groups for Pd-catalyzed sp(2) and sp(3) C-H functionalization reactions. The C-H functionalization products can be subsequently transformed into ortho- or beta-functionalized ketones, alcohols, amines, and heterocycles.
acetates and xanthates for the synthesis of thiazol-2-yl ethers with remarkable regioselectivity has been developed. Various oxime acetates, whether derived from aryl ketones or alkyl ketones, or natural product cores are suitable for this conversion. Unique dihydrothiazoles were also obtained when both reaction sites were methine. Mechanistic studies indicated that imino copper(III) intermediates were involved
A novel copper-catalyzedC(sp3)-H oxidative functionalization of aromatic oxime acetates with [small alpha]-oxocarboxylic acids was reported. This process involved N-O/C-C bondcleavages and C-C bond formations to furnish substituted enaminones under...
Copper(0)/PPh<sub>3</sub>-Mediated Bisheteroannulations of <i>o</i>-Nitroalkynes with Methylketoximes Accessing Pyrazo-Fused Pseudoindoxyls
作者:Huanxin Meng、Zhenhua Xu、Zhonghua Qu、Huawen Huang、Guo-Jun Deng
DOI:10.1021/acs.orglett.0c02180
日期:2020.8.7
A copper(0)/PPh3-mediated cascade bisheteroannulation reaction of o-nitroalkynes with methylketoximes has been developed that provides viable access to a diverse range of pyrazo-fused pseudoindoxyl compounds. Synthetically useful functional groups including sensitive C–I bonds are compatible with this system. Mechanistic studies suggest a reaction cascade involving sequential PPh3-mediated deoxygenative
Direct synthesis of 2-methylpyridines <i>via</i> I<sub>2</sub>-triggered [3 + 2 + 1] annulation of aryl methyl ketoxime acetates with triethylamine as the carbon source
A facile and efficient [3 + 2 + 1] annulation of aryl methyl ketoximeacetates and triethylamine for the synthesis of 2-methylpyridines was disclosed. This reaction demonstrated that I2 was effective in triggering N–O bond cleavage of oxime acetates generating imine radicals. It was noteworthy that this transformation employed triethylamine as the carbon source for the direct formation of pyridines