A Novel Approach to the Efficient Oxygenation of Hydrocarbons under Mild Conditions.Superior Oxo Transfer Selectivity Using Dioxiranes

摘要

The design of efficient and general methods for the selective oxy-functionalization of unactivated carbon-hydrogen bonds continues to represent a major challenge for the community of chemists,despite the fact that the oxidation of alkanes is a major feature of the chemical economy.A low level of selectivity is characteristic of large-scale oxidation of hydrocarbons performed under customary industrial oxidizing conditions (e.g.,the catalytic air oxidation of cycloalkanes);in these processes,selectivity is difficult to control,because they are often impacted by the usual problems associated with free-radical chain reactions.Thus,in the last decades much work has been devoted to the search for general methods of selective oxidation that could be applied to a variety of satured hydrocarbons.In this context,just a few leading methods appear encouraging at the present time.This Account addresses a new approach developed in our laboratory,consisting in the application of isolated dioxiranes,a class of powerful yet selective oxidants.We contend that the method shows promise to contribute resolution of a well-recognized general problem in the existing chemistry of alkanes,that is,to achieve efficient oxyfunctionalizations with high selectivity for simple as well as structurally complex targets.