Geminal dehydrogenation of a C(sp3) CH2 group by unsaturated Ru(II) or Os(II)

Abstract

Dimeric [RuHClL₂]₂ (L = PPr₃ⁱ), a source of the 14-electron fragment RuHClL₂, reacts at reflux in THF to cleanly form equimolar L₂HClRuC(CH₂)₃O and RuHCl(H₂)L₂, the products of stoichiometric geminal dehydrogenation of the α-C of THF. The same products are produced slowly at 25 °C by reaction of the transient RuHClL₂. Double dehydrogenation of the sp³ α-C of THF is also effected at 25 °C by Os(H)₃ClL₂ if two H ligands are removed with Bu^t(H)CCH₂.