Copper-catalyzed oxidative cyclization of chalcone and benzylic amine leading to 2,5-diaryl oxazoles via carbon–carbon double bond cleavage
作者:Dongfang Liu、Jintao Yu、Jiang Cheng
DOI:10.1016/j.tet.2013.12.077
日期:2014.2
oxidative cyclization of chalcone with benzylic amine is achieved, providing 2,5-diaryl oxazoles in moderate to good yields. The procedure employs O2 as a clean oxidant and involves an oxidative cleavage of the CC bond as the key step.
Synthesis of Oxazoles through Copper-Mediated Aerobic Oxidative Dehydrogenative Annulation and Oxygenation of Aldehydes and Amines
作者:Zejun Xu、Chun Zhang、Ning Jiao
DOI:10.1002/anie.201206382
日期:2012.11.5
A fragment‐assembling strategy is used to form oxazoles from aryl acetaldehydes, amines, and molecular oxygen under mild conditions (see scheme). The transformation is highly efficient with the removal of six hydrogen atoms, including the cleavage of four C(sp3)H bonds.
Iodine catalyzed synthesis of 2,5-substituted oxazoles from N-arylethylamides through intramolecular C(sp3)–H functionalization under metal-free conditions is described.