有機触媒による酸化的炭素-炭素二重結合切断反応

抄録

Oxidative cleavage of carbon–carbon double bonds to carbonyl compounds is an essential operation in organic synthesis. Ozonolysis is generally accepted as the standard method for this direct transformation. However, its utility is often limited by safety concerns. Use of high–valent oxometals such as RuO₄, OsO₄, and MeReO₃ in combination with a number of oxygen donors as stoichiometric oxidants is suitable for the oxidative catalytic cleavage of olefins, but they are expensive and/or toxic. Therefore, the development of a safe and environmentally friendly procedure for the cleavage of carbon–carbon double bonds is highly desirable. In this review, we report a safe, environment–friendly, and heavy metal–free ozonolysis of olefins, which involves activated iodosylbenzene monomers, hydroxy–λ³–iodanes, as active species. Organocatalytic version of the oxidative cleavage of olefins that involves in situ generation of hypervalent aryl–λ³–iodanes as effective organocatalysts and the use of m–chloroperbenzoic acid as a stoichiometric terminal oxidant under metal–free conditions is described. Cyclic and acyclic olefins as well as aliphatic and aromatic alkynes were cleaved to carboxylic acids under the organocatalytic conditions.