Construction of -Acyliminophosphoranes via Iron(II)-Catalyzed Imidization of Phosphines with -Acyloxyamides.

Employing FeCl as a cheap and readily available catalyst, a facile imidization of phosphines with -acyloxyamides is described, affording synthetically useful acyliminophosphoranes with high functional group tolerance. The transformation is easily performed under an air atmosphere at room temperature and could be scaled up to gram scale with a catalyst loading of 1 mol %. The iminophosphoranyl moiety in the product was further utilized as an effective directing group for controllable C(sp)-H bond amidations under Rh(III) catalysis.