Diastereoselective ZnCl-Mediated Joullié-Ugi Three-Component Reaction for the Preparation of Phosphorylated -Acylaziridines from 2-Azirines.

We disclose a direct approach to the diastereoselective synthesis of phosphorus substituted -acylaziridines based on a one-pot ZnCl-catalyzed Joullié-Ugi three-component reaction of phosphorylated 2-azirines, carboxylic acids and isocyanides. Hence, this robust protocol offers rapid access to an array of -acylaziridines in moderate-to-good yields and up to 98:2 dr for substrates over a wide scope. The relevance of this synthetic methodology was achieved via a gram-scale reaction and the further derivatization of the nitrogen-containing three-membered heterocycle. The diastereo- and regioselective ring expansion of the obtained -acylaziridines to oxazole derivatives was accomplished in the presence of BF·OEt as an efficient Lewid acid catalyst.