Carbon-hydrogen bond activation by iridium(III) complexes.

摘要

This work focuses on C–H bond activation by Ir(III) complexes. A key result in the research presented here is a rare double C–H activation of an activated CH₂ group that provides a mild and fast synthetic method to generate Fischer carbene complexes of indium. The first C–H activation is an overall cyclometalation of 2-diakylaminopyridine substrates (py-NR₂, py = 2-pyridyl, R₂ = Me₂, E _t2, or (CH₂)₄) to a Ir(III) center, while the second one, a reversible α-H elimination, leads to the formation of Ir(III) Fischer carbenes. Chapter 2 describes the synthesis and characterization of these Fischer carbene complexes of indium prepared by the reaction of 2-diakylaminopyridines with [IrH₂(OCME₂)₂L₂]BF₄ (1) or [Ir(COD)L₂]BF₄ (2) (L = PPh₃) in CH₂Cl₂ at 25°C. Chapter 3 discusses the mechanistic considerations for the formation of the carbenes from 1 as well as the rationale for 1 to act as a catalyst for the selective isotope exchange.; Chapter 4 describes the H/D isotope scrambling between alkenes and IrD₂(O₂CCF₃)(PAr₃)₂ d2-3, Ar = p-FC₆H ₄) via an alkane complex as the intermediate, in order to understand photochemical and thermal alkane activation with 3.