Advances in the reduction of quinolines to 1,2,3,4‐tetrahydroquinolines

Abstract The pursuit of modern sustainable chemistry has stimulated the development of innovative catalytic processes that enable chemical transformations to be performed under mild and clean conditions with high efficiency. Herein, we report that the hydrogenation of heteroaromatic compounds is one of the most efficient methods for the construction of heterocyclic skeletons, and only a few promising progress has been achieved. Transition metal‐catalyzed, a countless number of transition metals include have been used toward the development of homo/heterogeneous hydrogenation of quinolines via the most convenient route (Direct Hydrogenation) to obtain the corresponding tetrahydroquinoline derivatives.