Generation and electrophilic substitution reactions of 3-lithio-2-methyleneaziridines

2-Methyleneaziridinyl anions can be produced by selective deprotonation of the parent aziridine at C-3 using sec -BuLi/TMEDA. Subsequent reaction with a wide variety of electrophiles including MeI, ICH 2 CH 2 CH 2 CH 2 Cl, PhCH 2 Br, allyl bromide, Me 3 SiCl, Bu 3 SnCl, PhCHO and Ph 2 CO provides the corresponding C-3 substituted derivatives in moderate to good yields (43–91%). In the case of homochiral methyleneaziridines bearing an ( S )-α-methylbenzyl group on nitrogen, high levels of diastereocontrol (up to 90%de) can be achieved in this lithiation/alkylation sequence.