Chaoxiang Ning, Jiye Shu, Xiaojun Zeng, Xiaodong Xiong
High Resolution Image Download MS PowerPoint Slide A solvent-dependent approach to the oxidative ring opening of cyclopropylamides with NIS under mild reaction conditions has been developed. In the presence of hexane as the solvent, 3-iodo N,O -acetal was obtained in good yields, whereas employment of CCl 4 as the solvent favors the formation of 1,3-oxazines. This divergent method avoids the use of an external base, an acid, and a metal and exhibits excellent functional-group tolerance. Primary mechanistic studies revealed that halogen bonding facilitates the nucleophilic attack of 3-iodo N,O -acetal to 1,3-oxazine.