An effective and selective non-heme iron-catalyzed hydroxylation of alkane C-H bonds

Abstract

Selective hydroxylation of non-activated alkyl C-H bonds remains a contemporary challenge in organic synthesis, while these transformations in nature are mainly mediated by iron-dependent enzymes under mild conditions. Herein, mononuclear nonheme iron complexes 1 and 2 demonstrate excellent selectivity in the oxidation of alkanes, including adamantane, cis-1,2-dimethylcyclohexane and cycloalkane under ambient conditions. The obtained alcohol/ketone (A/K) ratio of 93.8 and total turnover number of 128 are the highest ones up to date. Even under high water concentration, the catalyst shows high selectivity for alkane oxidation over water oxidation, indicating an unprecedented selectivity in the cyclohexane oxidation. A high-valent intermediate of metal-based FeV(O) species, was proved to be responsible for the high selectivity in alkanes oxidation.