A Lewis Acid Catalyzed Annulation to 2,1-Benzisoxazoles

作者:Otley Kate D; Ellman Jonathan A*
来源:Journal of Organic Chemistry, 2014, 79(17): 8296-8303.
DOI:10.1021/jo5015432

摘要

We report here a new, atom economical annulation to 2,1-benzisoxazole scaffolds via the BF3 center dot Et2O-catalyzed reaction of glyoxylate esters and nitrosoarenes. The developed method represents a convergent route to this compound class from previously unexplored inputs and provides a range of 2,1-benzisoxazoles in moderate to high yields under convenient conditions. Along with exploration of substrate scope, initial mechanistic investigation through O-18 labeling and the synthesis of a reaction intermediate provides evidence for an unusual umpolung addition of glyoxylates to nitrosobenzenes with high O-selectivity, followed by a new type of Friedel-Crafts cyclization.

  • 出版日期2014-9-5

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