C-Methylation of Organic Substrates: A Comprehensive Overview. Part I. Methane as a Methylating Agent

A literature survey on C-methylation of organic substrates with methane as a methylating agent is analyzed. Of the substrates that undergo C-methylation are benzene, naphthalenes, toluene, alkanes, alkenes, acetonitrile, and other functionalized organic compounds. None of these methylation reactions occur in the absence of a catalyst. A direct introduction of a methyl group on the carbon sites of a molecule is concomitant with the formation of other products, as a result of either a possible rearrangement or a further reaction with methane. Mechanistically, the C-methylation with methane proceeds oxidatively. The products selectivities depend on several factors, mainly on the acid/ base character of the solid catalyst.