Studies on the synthesis of α-iodoaziridines and improved conditions for the synthesis of alkyl-α-iodoaziridines using ClMgCHI2

α-Iodoaziridines are unusual motifs and intriguing structures for further functionalisation of the intact aziridine. The preparation of N-protected α-iodoaziridines is achieved through an addition-cyclisation reaction of LiCHI2 with imines. The effects of varying the N-group and using different carbenoids are investigated. Excellent cis-stereochemistry is achieved, except for N-carbamates containing aryl groups. Using the mixed carbenoid LiCHICl, the iodide leaving group is selected for cyclisation affording chloroaziridines only, as a cis/trans mixture. More convenient and higher yielding conditions for the preparation of alkyl N-Ts α-iodoaziridines are developed, using ClMgCHI2. Additionally, the formation of the problematic primary alkyl α-iodoaziridines is achieved.