Lewis Base Promoted [4+2] Annulation of <i>o</i>‐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.