Carbocatalysis in Liquid-Phase Reactions.

There is broad interest in metal-free catalysis for sustainable chemistry. Carbocatalysis is a "green" option for catalytic transformations in the gas phase as well as in the liquid phase. This is evident by the numerous reports on gas-phase dehydrogenation and selective oxidation where carbon can be used as a successful alternative to metal oxide systems. Carbocatalysis for liquid-phase reactions, especially for organic synthesis, is an emerging research discipline and has undergone rapid development in recent years. This Review provides a critical analysis on the state-of-the-art of carbocatalysts for liquid-phase reactions, with a focus on the underlying mechanisms as well as the advantages and limitations of metal-free carbocatalysts.