ChemInform Abstract: NIS‐Mediated Oxidative Cyclization of N‐(2‐Trifluoromethyl‐3‐alkynyl) Hydroxylamines: A Facile Access to 4‐Trifluoromethyl‐5‐acylisoxazoles.

Abstract

Hydroxylamines: A Facile Access to 4-Trifluoromethyl-5-acylisoxazoles. -The reaction tolerates activated and deactivated aryl substituents as well as higher perfluorated alkyl residues but fails with terminal alkynes and TMS-terminated alkynes. At low temperatures, the related oxime (VII) as key intermediate can be isolated prior to oxidative cyclization. Further synthetic utilization is demonstrated by the transformation of compound (IIb) to pharmaceutically interesting compound (VIII) in 41% overall yield. -(ZHANG, L.; ZENG, Q.; MAO, A.; WU, Z.; LUO, T.; XIAO*, Y.; ZHANG, J.; Org. Biomol. Chem. 12 (2014) 44, 8942-8946, http://dx.