Unexpected migration and oxidative cyclization of substituted 2-acetophenone triflates under basic conditions: Synthetic and mechanistic insights

…, KE Bianco, BP Boscoe, PR Brooks…

Index: Coe, Jotham W.; Bianco, Krista E.; Boscoe, Brian P.; Brooks, Paige R.; Cox, Eric D.; Vetelino, Michael G. Journal of Organic Chemistry, 2003 , vol. 68, # 26 p. 9964 - 9970

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Citation Number: 14

Abstract

Oxidative ring closure of alkyl-substituted 2-hydroxyacetophenone trifluoromethanesulfonate esters (triflates) occurs upon exposure to base in anaerobic DMF at 20-90° C. Alkyl substitution is required for ring closure. A migrated enol triflate product forms at lower temperature in high yield via migration of the trifluoromethanesulfonate in the unsubstituted and monoalkyl-substituted cases. The alkyl-substituted enol triflates also enter into the ...