Catalysts refer to a substance that changes the chemical reaction rate (increasing or decreasing) of a reactant in a chemical reaction without changing the chemical equilibrium, and whose mass and chemical properties are not changed before and after the chemical reaction. According to the International Union of Pure and Applied Chemistry (IUPAC), 1981, a catalyst is a substance that changes the rate of reaction but does not change the total standard Gibbs free energy. Organocatalysts are catalysts containing only carbon, hydrogen, sulfur, and other non-metallic elements.
Organocatalysts can catalyze a variety of reactions, which can be divided into activation reactions(enamine activation, SOMO activation, hydrogen bond activation, chiral phase-transfer activation and nitrogen heterocyclic carbene activation), oxidation reactions, condensation reactions, carbonyl reduction reactions and oxo synthesis reactions according to the catalytic mechanism.
Oxidation reaction: The action of introducing organic matter into oxygen or dehydrogenating during the reaction of organic matter is called oxidation. The essence of the oxidation reaction is that the substance loses electrons.
Each method of making a catalyst is actually a combination of a series of operating units. Traditional methods include mechanical mixing, precipitation, spray evaporation, hot melt method, etc. And the new methods are chemical bonding, fiberization, etc.
Figure 1. Organic sulfur hydrolysis catalyst
Phase Transfer Catalysts