Molecular Diversity of Base Promoted Annulation of MBH Carbonates of Isatins and Dialkyl But‐2‐ynedioates

Abstract

AbstractDABCO promoted one‐pot three‐component reaction of aromatic amines, dialkyl but‐2‐ynedioates and MBH nitriles of isatins selectively afforded two diastereomeric spiro[indoline‐3,4′‐pyridines] in comparable yields. On the other hand, DABCO promoted cyclization of dialkyl but‐2‐ynedioates and MBH carbonates of isatins in DCM at room temperature gave spiro[cyclopentane‐1,3′‐indoline] derivatives, while the reaction of dialkyl but‐2‐ynedioates and MBH nitriles of isatins in chloroform at 70 °C resulted in unique cyclopenta[c]quinolone derivatives with ring‐opening of isatin moiety. A plausible reaction mechanism was rationally proposed to explain formation of the different products.