Tandem Pd-catalyzed C–C coupling/recyclization of 2-(2-bromoaryl)cyclopropane-1,1-dicarboxylates with primary nitro alkanes
摘要:
The first successful synthesis of 1H-2,3-benzoxazine 3-oxides has been described. The efficiency of the approach is provided by the C-C-coupling of 2-(2-bromoaryl)cyclopropane-1,1-dicarboxylates with primary nitroalkanes catalyzed by Pd(dba)(2)/JohnPhos system followed by in situ recyclization of the intermediates. Several representative transformations allowing selective modification of the nitronate as well as malonate functionalities in the resulting compounds are demonstrated. (C) 2015 Elsevier Ltd. All rights reserved.