Direct conversion of indoles to 3,3-difluoro-2-oxindoles via electrophilic fluorination.

Org Lett

Organic Chemistry, Institute of Chemical and Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, The Helios Block, #03-08, Singapore 138667.

Published: November 2012

3,3-Difluoro-2-oxindoles can be obtained directly from indoles in moderate yields via electrophilic fluorination using N-fluorobenzenesulfonimide as a mild fluorinating reagent. The presence of tert-butyl hydroperoxide during the reaction, together with additional heating after quenching the reaction with triethylamine, is beneficial to the formation of the desired product.

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http://dx.doi.org/10.1021/ol302666dDOI Listing

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