Herein, the first acceptorless dehydrogenation of tetrahydroquinolines (THQs), indolines, and other related N-heterocycles, by merging visible-light photoredox catalysis and cobalt catalysis at ambient temperature, is described. The potential applications to organic transformations and hydrogen-storage materials are demonstrated. Primary mechanistic investigations indicate that the catalytic cycle occurs predominantly by an oxidative quenching pathway.

Herein, the first acceptorless dehydrogenation of tetrahydroquinolines (THQs), indolines,a nd other related Nheterocycles,bymerging visible-light photoredox catalysis and cobalt catalysis at ambient temperature,i sd escribed. The potential applications to organic transformations and hydrogen-storage materials are demonstrated. Primary mechanistic investigations indicate that the catalytic cycle occurs predominantly by an oxidative quenchingpathway. Scheme 1. Strategies for acceptorless dehydrogenation of THQs. Scheme 2. Possible pathway for dehydrogenation of THQs.

Formaldehyde (CH2O) has been used as a key platform reagent in the chemical industry for many decades. In the current stage, the industrial production of CH2O mainly depends on the...

Lignocellulosic biomass is one of the most abundant renewable sources in nature. Herein, we have developed the utilization of renewable formic acid from lignocellulosic biomass as a hydrogen source and a carbon source for the selective hydrogenation and further N-methylation of various quinolines and the derivatives, various indoles under mild conditions in high efficiencies. N-methylation of various anilines is also developed. Mechanistic studies indicate that the hydrogenation occurs via a transfer hydrogenation pathway.[a] C.