An Unexpected Highly Stereoselective Bisaziridination of (E,E)-1,4-Dialkyl-2,3-dinitrobutadienes Followed by a Nitro Group Driven Ring Enlargement
文摘
(±)-2,2′-Dinitro-2,2′-biaziridines were obtained by a direct aza-MIRC (Michael initiated ring closure) reaction on (E,E)-1,4-dialkyl-2,3-dinitro-l,3-butadienes under very mild conditions. The reactions occur with high stereoselectivity as shown by the enantioselective HPLC analyses performed on the crude mixtures. Ring enlargement to 3,3′-bi(1,2,4-oxadiazole) derivatives was easily obtained by a simple treatment with sodium iodide in DMSO, with an unforeseen regioselective aziridine C−C cleavage.