A DIRECT ROUTE TO C-VINYLAZIRIDINES - REACTION OF N-SUFONYLMINES WITHALLYLIC YLIDES UNDER PHASE-TRANSFER CONDITIONS OR WITH PREFORMED YLIDES AT LOW-TEMPERATURE

Allylic sulfonium salts 3, 5, 7, 11, 12, 13, and arsonium salt 14 reac t with aromatic, heteroaromatic, and (alpha,beta-unsaturated N-sulfony limines under solid-liquid phase-transfer conditions in the presence o f KOH at room temperature to produce, respectively, vinyl-, (beta>-phe nylvinyl)-, and [beta-(trimethylsilyl)vinyl]aziridines in excellent yi elds within several minutes. In some cases, pyrroline compound 9 is ob tained as a minor product. This aziridination reaction has also been c arried out with preformed ylides, generated from sulfonium salts 3, 7, arsonium salt 14, and telluronium salts 15, 16 with a base in THF at -78 degrees C. In most examples, quantitative yields were achieved. Ho wever, the trans/cis selectivity of the reaction was not high in eithe r case. A semistable allylic sulfonium ylide, i.e., dimethylsulfonium 3-(trimethylsilyl)allylide, was found to not undergo an expected [2,3] -sigma-rearrangement and so can also be used in this reaction.