The diastereoselective synthesis and reactions of beta-azido vinyl esters from enol triflates

The diastereoselective synthesis of beta-azido vinyl esters is presented. Using stereodefined enol triflates developed in the Frantz lab, highly substituted (E/Z)-vinyl azides are accessed by performing conjugate additions of sodium azide with the corresponding (E/Z)-enol triflate in DMF to yield the desired azide in stereoselective fashion. Further investigation of these vinyl azides demonstrates their ability to exhibit differential reactivity leading to various heterocycles. When (E/Z)-vinyl azides are exposed to heat, the formation of a nitrene intermediate occurs. By strategically providing various substitution patterns on these nitrene intermediates, a pathway to specific heterocycles including azirines, isoxazoles, and pyrroles is feasible.