Efficient and rapid synthesis of N-substituted isoquinolin-1-ones under mild conditions: Facile access to doryanine derivatives

We describe the simple and efficient synthesis of N-substituted isoquinolin-1-one derivatives. Initiating with the coupling of benzoic acids containing vinyl ethers with different amines, followed by rapid intramolecular cyclization under acidic conditions at room temperature, N-substituted isoquinolin-1-ones were furnished in high yields. The utility of this simple and mild cyclization method was demonstrated through the practical synthesis of natural product doryanine and its analogues. (C) 2019 Elsevier Ltd. All rights reserved.