Three component reactions of olefins, amines, and sulfur were studied. Thioamidation of styrenes is base-controlled, and 2-phenylethanethioamides and benzothioamides were obtained selectively in the presence of two different bases. This protocol offers a simple and efficient procedure for the synthesis of thioamides.
Photochemical cyclization of thioformanilides by chloranil: An approach to 2-substituted benzothiazoles
作者:Valentina Rey、Silvia M. Soria-Castro、Juan E. Argüello、Alicia B. Peñéñory
DOI:10.1016/j.tetlet.2009.06.020
日期:2009.8
2-Substituted benzothiazoles were efficiently synthesized by radical cyclization of thioformanilides induced by chloranil under irradiation in 1,2-dichloroethane and toluene at 80 degrees C. Hydrogen atom abstraction from thiobenzamide by triplet chloranil was the key step of the mechanism, as confirmed by UP experiments. The methodology developed is simple and afforded the easily isolated products from moderate to good yield. (C) 2009 Elsevier Ltd. All rights reserved.