Lewis Base Promoted [4+2] Annulation of o-Acylamino-Aryl Morita-Baylis-Hillman Carbonates With Isatylidene Malononitriles: Facile Access to Spiro[Indolin-3,2′-Quinoline] Frameworks

Abstract

A novel [4+2] annulation reaction between o-acylamino-aryl MBH carbonates and isatylidene malononitriles has been successfully developed. This methodology exhibits excellent substrate tolerance, affording a series of spiro[indolin-3,2′-quinoline] framework compounds with yields up to 98%. The scalability of the reaction is also noteworthy, as evidenced by the 95% yield of the final product upon a 50-fold scale-up.