Mononuclear Ruthenium and Osmium Complexes with a Bicyclic Guanidinate Ligand: Synthesis and Catalytic Behavior in Olefin Isomerization Processes

摘要

> The preparation of the first mononuclear Ru II , Ru IV , and Os II complexes containing the anion of the bicyclic guanidine 1,3,4,6,7,8‐hexahydro‐2 H ‐pyrimido[1,2‐ a ]pyrimidine (Hhpp) as a chelating ligand, namely [RuX{κ 2 ‐( N , N′ )‐hpp}(η 6 ‐arene)] [arene = p ‐cymene, X = Cl ( 2a ), Br ( 2b ), I ( 2c ); arene = C ₆ Me ₆ , X = Cl ( 7 )], [RuCl{κ 2 ‐( N , N′ )‐hpp}(η 3 :η 3 ‐C ₁₀ H ₁₆ )] ( 9 ; C ₁₀ H ₁₆ = 2,7‐dimethylocta‐2,6‐diene‐1,8‐diyl), and [OsCl{κ 2 ‐( N , N′ )‐hpp}(η 6 ‐ p ‐cymene)] ( 11 ), is described. Compounds 2a – c , 7 , 9 , and 11 have been fully characterized by elemental analysis, HRMS, IR and NMR spectroscopy. In addition, the structure of 2a has been unequivocally confirmed by single‐crystal X‐ray diffraction methods. The catalytic behavior of these metal guanidinate complexes in the base‐free redox isomerization of allylic alcohols is explored, with the ruthenium(IV) deri