Electrophilic Cyclization of o-Anisole- and o-Thioanisole-Substituted Ynamides: Synthesis of 2-Amidobenzofurans and 2-Amidobenzothiophenes
Yulong Kong, Lian Yu, Lingzi Fu, Jian Cao*, Guoqiao Lai, Yuming Cui, Ziqiang Hu, Guanhai Wang
*Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Wenyi Road 222, Hangzhou 310012, P. R. of China, Email: caojianhznu.edu.cn
Y. Kong, L. Yu, L. Fu, J. Cao, G. Lai, Y. Cui, Z. Hu, G. Wang, Synthesis, 2013, 45, 1975-1982.
see article for more reactions
Electrophilic cyclization of o-anisole- and o-thioanisole-substituted ynamides with I2, NBS and NCS gives 3-halogenated 2-amidobenzofurans and 2-amidobenzothiophenes. Some 3-iodo-2-amidobenzofurans were further transferred into 3-aryl-, 3-alkynyl, and 3-vinyl-2-amidobenzofurans via Pd-catalyzed cross coupling reactions.
see article for more examples
2-amidobenzofurans, 2-amidobenzothiophenes, electrophilic cyclization, ynamide, cross-coupling reaction