A mild, practical, and simple procedure for phenyl selenoesters synthesisfrom several anhydrides and diphenyl diselenide was developed. This transition-metal-free method provides a straightforward entry to storable Fmoc-amino acid selenoesters which are effective chemoselective acylating reagents. An application to oligopeptide synthesis was illustrated.
Indium-mediated cleavage of diphenyl diselenide and diphenyl disulfide: efficient one-pot synthesis of unsymmetrical diorganyl selenides, sulfides, and selenoesters
作者:Wanida Munbunjong、Eun Hwa Lee、Poonlarp Ngernmaneerat、Sung Jun Kim、Gurpinder Singh、Warinthorn Chavasiri、Doo Ok Jang
DOI:10.1016/j.tet.2009.01.072
日期:2009.3
convenient and efficient method was developed for the synthesis of alkyl phenyl selenides, sulfides, and selenoesters in one-pot reaction by using indium metal. The reaction showed the selectivity for tert-alkyl, benzylic, and allylic halides over primary and secondary alkyl halides. For the reaction of primary and secondary alkyl iodides and bromides, the yields of selenides were improved by the addition
selenoesters 1c and 1i with diazomethane resulted in crossover, with the formation of all four possible α-seleno ketones 2b, 2c, 2h and 2i. A non-concerted mechanism involving attack by the diazo compound upon the acyl carbon atom of an activated selenoester with the formation of a tetrahedral intermediate 11 has been suggested. The reaction of the selenothiocarbamate 4 with diazomethane resulted in 1,3-dipolar
Attempting to apply the in situ production of PhSeZnSePh to the synthesis of selenoesters, an unexpected reaction involving the solvent (tetrahydrofuran) was observed and studied. We reported here some evidences about the mechanism and the possibility to control the chemoselectivity of this new reaction that afforded the formation of interesting selenoderivatives in which the selenium moiety and the carboxylic