Catalytic Functionalization of Un-activated Primary C-H Bonds

Hartwig et al. have reported the site-selective, catalytic functionalization of un-activated primary C-H bonds controlled by a hydroxyl group in the same molecule. First, (hydrido)silyl ethers are formed by the reaction of alcohols or ketones with diethylsilane in the presence of [Ir(cod)OMe]₂ catalyst. Second, dehydrogenative functionalization between the Si-H bond and γ-position of a primary C-H bond of the silyl ethers occurs with the use of [Ir(cod)OMe]₂ and 3,4,7,8-tetramethyl-1,10-phenanthroline as catalysts and a ligand, 2-norbornene, is used as a hydrogen acceptor, to form the oxasilolanes. Subsequent Tamao—Fleming oxidation of the oxasilolanes yields a 1,3-diol. Since this reaction can be applied to various alcohols and ketones, it has broad applicability to the synthesis of natural products.