GaCl3-Catalyzed Ortho-Ethynylation of Phenols
Katsumi Kobayashi, Mieko Arisawa and Masahiko Yamaguchi*
*Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai 980-8578, Japan, Email: yamamail.pharm.tohoku.ac.jp
K. Kobayahi, M. Arisawa, M. Yamaguchi, J. Am. Chem. Soc., 2002, 124, 8528-8529.
DOI: 10.1021/ja026108r (free Supporting Information)
Various substituted phenols are ethynylated at the ortho position with silylated chloroethyne in the presence of a catalytic amount of GaCl3 and lithium phenoxide. The lithium salt is essential for the catalysis, and addition of 2,6-di(tert-butyl)-4-methylpyridine inhibits desilylation and hydration of the products. The mechanism is discussed.
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