Amides and Ethers as Chemoselective Surrogates for Copper(II)-Catalyzed ortho Benzoyloxylation of 2-Phenylpyridines
摘要:
Chemoselective ortho benzoyloxylation of 2-phenylpyridine derivatives using amides and ethers as novel arylcarboxy sources using a Cu(II)/TBHP catalytic system has been reported. It is a simple protocol for ortho benzoyloxylation using amides and ethers as surrogates. A broad range of amides and ethers was found to be compatible under optimized reaction conditions to provide the corresponding products in good to excellent yield. The reaction proceeds through the cleavage of C-N, C-O, and C-H bonds and the formation of a new C-O bond via C-H functionalization.
Copper catalyzed oxidative ortho-C–H benzoxylation of 2-phenylpyridines with benzyl alcohols and benzyl amines as benzoxylation sources
作者:Ashok B. Khemnar、Bhalchandra M. Bhanage
DOI:10.1039/c4ob01912a
日期:——
An efficient methodology for the ortho benzoxylation of 2-phenylpyridine via C–H bond activation using benzyl alcohols and benzyl amines as arylcarboxy sources has been developed.
A palladium-catalyzed direct C–H bond oxidativeacyloxylation of 2-arylpyridines with aromatic carboxylic acids is described. Several 2-arylpyridines derivatives and aromatic carboxylic acids participate in the reaction, providing a series of mono-acyloxylated products in moderate to good yields. Importantly, the reaction can be conducted without using any ligands in a lower temperature.
A domino oxidation-acyloxylation reaction of 2-arylpyridines with aldehydes or methylarenes under the catalysis of Cu(OAc)2 has been developed. The strategy via C-H bond functionalization has the advantages of good functional-group tolerance, high ortho regioselectivity and no need of any ligand or additive.