K2CO3-Catalyzed Synthesis of Chromones and 4-Quinolones through the Cleavage of Aromatic C–O Bonds
摘要:
Phenol-derived electrophiles are favorable substrates because phenols are naturally abundant or can be readily prepared from other aromatic compounds. However, the cleavage of aromatic C-O bonds Is a great challenge because of their high energy. K2CO3-catalyzed intramolecular cyclization of 1-(2-alkoxyphenyl)-3-akylpropane-1,3-dlone and 3-(alkylimino)-1-(2-methoxyphenyl)-2-methylpropan-1-one derivatives via the selective cleavage of aromatic C-O bonds Is reported. The corresponding chromone and 4-quinolone derivatives were obtained in reasonable yields.
Iodine-Catalyzed Synthesis of 1,2-Diaryldiketones by Oxidative Cleavage of 1,3-Diaryldiketones with DMSO
作者:Yu Yuan、Haitao Zhu
DOI:10.1002/ejoc.201101028
日期:2012.1
A metal-free, efficient, practical, and convenient process based on an iodine-catalyzedoxidativecleavage reaction has been developed to form 1,2-diaryldiketons in high yields from 1,3-diaryldiketones. The reaction is performed in DMSO and in air, and a mechanism was proposed according to the reaction evidence.
An nBu4NI-catalyzed oxidative cross-dehydrogenative-coupling of β-dicarbonyl compounds with acetone undermild reaction conditions is described. This methodology provides a straightforward pathway to synthesize 2-carbonyl-1,4-diketones and features a simple system, low reaction temperature, and environmental friendliness.