Highly Enantioselective Synthesis of Dihydroquinazolinones Catalyzed by SPINOL-Phosphoric Acids

The asymmetric condensation/amine addition cascade sequence of 2-aminobenzamides and aldehydes catalyzed by chiral spirocyclic SPINOL-phosphoric acids was realized. SPINOL-phosphoric acid 1j was found to be a general, highly enantioselective organocatalyst for such cascade reactions at room temperature, affording 2,3-dihydroquinazolinones in excellent yields (up to 99%) with good to excellent ee's (up to 98%). The best level of stereocontrol was obtained for aromatic aldehydes with an ortho substituent.