Divergent de novo construction of α-functionalized pyrrole derivatives via coarctate reaction

Pyrroles are important structural units of natural products, drug molecules, biomolecules and functional material molecules. Efficient synthesis of α-functionalized pyrroles with different substituents from easily accessible starting materials is still challenging. Herein, a facile and regioselective coarctate reaction of enynals involving a free carbene intermediate has been developed, which allows the divergent and practical de novo synthesis of various α-furanyl pyrroles and α-cyclopropenyl pyrroles derivatives with good to excellent yields and high efficiency under mild conditions. This approach features readily accessible starting materials, high functional group compatibility, step economy and scalability, which would complement previous methods and support expansion of the toolbox for the synthesis of valuable, but previously inaccessible, highly substituted and electron-rich α-functionalized pyrroles.