[Omim]Cl/FeCl3-catalyzed cross-dehydrogenative-coupling of 1,4-benzoxazinones with various indoles

A novel C(sp 3 )–C(sp 2 ) cross-dehydrogenative-coupling procedure was developed for the reaction of benzoxazin-2-ones with indole derivatives. Thus, ionic liquid-mediated coupling of 1,4-benzoxazinone derivatives with indoles were observed in which [Omim]Cl/FeCl 3 acted as both the solvent and the catalyst. Under [Omim]Cl/FeCl 3 -TBHP conditions, derivatives of 1 coupled at room temperature with indoles bearing various substituents to give the target products in good yields and within 0.5–2 h time period. The procedure is relatively environmentally friendly and is applicable to several derivatives of both reactants to access the desired products.