Use of iodoacetylene as a dipolarphile in the synthesis of 5-iodoisoxazole derivatives

…, T Grieme, P Sharma, YM Pu, P Raje, H Morton…

Index: Ku, Yi-Yin; Grieme, Tim; Sharma, Padam; Pu, Yu-Ming; Raje, Prasad; Morton, Howard; King, Steve Organic Letters, 2001 , vol. 3, # 26 p. 4185 - 4187

Full Text: HTML

Citation Number: 27

Abstract

Iodoacetylene 1 was prepared in situ from the reactions of ethynylmagnesium bromide or tributyl (ethynyl) tin with iodine. It was used as a dipolarphile in the [2+ 3] cyclization reaction with 1, 3-dipolar nitrile oxide derivatives to produce 2-(5-iodoisoxazol-3-yl) pyridine 2 and 3- (4-fluorophenyl)-5-iodoisoxazole 8 in good yield (70-90%). Subsequently, several 5- substituted isoxazole derivatives 3 were obtained by Pd-catalyzed reactions.