Scandium(III) triflate-TMSCl promoted cyclization of aziridin-1-yl oximes to 5,6-dihydro-4H-[1,2,4]oxadiazines

A convenient and facile one-pot synthesis of 5,6-dihydro-4H-[1,2,4]oxadiazine is described. Treatment of aziridin-1-yl-oximes with Scandium(III) triflate readily afforded 5,6-dihydro-4H-[1,2,4]oxadiazine in the presence of chlorotrimethylsilane.