Alkanes to carboxylic acids in aqueous medium: metal-free and metal-promoted highly efficient and mild conversions

摘要

A convenient and clean route to transform, in aqueous medium, various alkanes to carboxylic acids via single-pot carboxylation with CO and water, under mild conditions, has been achieved, proceeding efficiently and selectively even without any metal catalyst and any acid additive, at low temperatures; the relevant hydroxylating role of H_2O and radical mechanisms are disclosed by radical-trap, H_2~(18)O and DFT studies.rnThe search for mild, selective, efficient and sustainable methods for the functionalization of alkanes (the main components of natural gas and oil) to yield more valuable products is a challenge to modern chemistry. However, the inertness of alkanes commonly requires the use of a metal catalyst and harsh conditions, e.g. strongly acidic media, typically cone. sulfuric acid, trifluoroacetic acid (TFA) or a superacid. The design of alternative and efficient routes under mild conditions and circumventing the use of toxic acid solvents and metals, i.e. preferably in aqueous medium, at low temperature and without a metal catalyst, is a relevant goal which has not yet been achieved.