摘要:
1,3-Selenazoles and 2-imidazolin-5-selones were synthesized by the reaction of isoselenocyanates (1) with alpha-lithiated isocyanides (11). Isocyanides having only one substituent at the alpha-carbon such as ethyl isocyanoacetate and benzyl isocyanide gave 1,3-selenazoles (9) in good yields. On the other hand, alpha,alpha-disubstituted isocyanides such as alpha-methylbenzyl isocyanide and diphenylmethyl isocyanide afforded 2-butylseleno-2-imidazolin-5-selones (18) after trapping with butyl iodide. The latter products were formed from one molecule of isocyanides and two molecules of isoselenocyanates. Plausible reaction pathways are proposed. (C) 1997 Elsevier Science Ltd.