From Two Components Intermolecular Cycloaddition Reactions

Attempts to prepare 1 //-azirines by the reaction of JV-aminonitrenes with alkynes have been unsuccessful, although convincing evidence for the intermediacy of 1//-azirines has been obtained by analysis of the products from such reactions 69CC147,71AHC(13)45, B-83MI 101-02,84CHEC-i(7)47 . 

Sulfur stabilized nitrenes have been implicated in aziridination reactions B-84MI 101-6, 92CC898, 94CPB27). An example using oxidative conditions is shown in Equation (60) 94CPB27 . The authors favor an (arenesulfenyl)nitrene intermediate. 

The addition of carbenes and carbenoids to imines and nitriles continues to be a popular approach to aziridines and 2//-azirines. These processes have been well reviewed by Deyrup (B-83MI101-01). Dichlorocarbene and other dihalocarbenes have been added to a wide variety of imines to provide dihaloaziridines. A recent example is shown in Equation (64), illustrating the use of phase-transfer conditions 93H(36)69i). The treatment of azides with excess dichlorocarbene results in the formation of the 2,2,3,3-tetrachloroaziridines (92TL2339). Presumably, the azide is converted by dichlorocarbene to the imidoyl dihalide RN=CC12 which reacts further with dichlorocarbene. Transition metal-promoted reaction of a-diazoesters with imines provides 2-(alkoxycarbonyl)aziridines B- 

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