Inter‐ and Intramolecular Thermal Activation of Aliphatic C–H Bonds Mediated by Complexes Containing the Fragments [{<i>C</i>y₂P(CH₂)_nPCy₂}M] (<i>n</i>=1–4, M = Rh, Ru)

Abstract

Abstract A well defined geometrical structure and a well established catalytic potential for a plethora of processes puts the chelate rings [{R 2 P&lt;(CH 2 ) n PR 2 }M] (M = Rh, Ru) among the most interesting candidates for catalytic alkane functionalization in homogeneous solution. It is demonstrated that intermolecular thermal C–H activation ( 3→4 ) is possible with readily accessible complexes [{Cy 2 P(CH 2 ) n PCy 2 }Rh(hfacac)] (n = 1–4, 1a – c and [Cy 2 P(CH 2 ) n PCy 2 }Ru(η 3 ‐C 4 H 7 ) 2 ] (n = 1 – 3 , 2a – c ) containing such fragments. A maximum of 5 catalytic cycles was achieved with complex 2a . In case of Ru complexes containing the same ligands with n =3 and 4, intramolecular cleavage of three adjacent C–H bonds in one of the cyclohexyl substituents at phosphorus also occurs readily leading to formation of a new polydentate k 2 P,P', η 3 ‐allyl ligand.