Copper-catalyzed cascade reaction of tryptamines with diazo compounds to access hexahydropyrroloindoline derivatives

A domino reaction sequence of cyclopropanation/ring-opening/iminium cyclization of tryptamine derivatives with donor-acceptor diazo compounds is developed to furnish pyrroloindolines, creating three consecutive stereogenic centers in a single step. The copper-catalyzed reaction provides pyrroloindolines at room-temperature with good substrate scope.

Automated summary

A domino reaction sequence has been developed for the synthesis of pyrroloindolines, in which tryptamine derivatives and donor-acceptor diazo compounds are used as substrates. This reaction simultaneously forms three consecutive stereogenic centers, providing a convenient and efficient strategy for the construction of complex molecules. Copper catalysis enables the reaction to proceed smoothly at room temperature, and a wide range of substrates can be employed.