One-pot synthesis of useful heterocycles in medicinal chemistry using a cascade strategy

To access useful heterocycles in medicinal chemistry such as pyridazinones, dihydropyrimidinones, and dihydropyrimidinthiones, a "green" mild and highly efficient one-pot triple cascade was developed involving a Claisen-decarboxylation, electrophilic reaction, and subsequent heterocyclization. In addition, indazoles and benzofurans could also be constructed via a double cascade. To develop the cascade process, a direct Claisen-decarboxylation reaction was firstly optimized. This reaction can then couple with electrophilic reactions including alkylation, Michael addition or aldol reaction to enable the preparation of various aryl ketones in a one-pot fashion.