Synthesis of Tetranuclear Ruthenium (Ii) Complex of Pyridyloxy-Substituted 2,2′-Dioxybiphenyl-Cyclotriphosphazene Platform and its Catalytic Application in the Transfer Hydrogenation of Ketones

GRAPHICAL ABSTRACT

Abstract

Cyclophosphazene was reacted with biphenyl-2,2’- diol to afford the N₃P₃Cl₄(O₂C₁₂H₈) (1). Then, pyridyloxy cyclophosphazene, spiro N₃P₃(O₂C₁₂H₈)(O‒C₅H₄N-3)₄ (2) was synthesized from the reaction of 3-hydroxy pyridine and compound 1. The reaction of 2 with [RuCl₂(p-cymene)]₂ afforded Ru(II) complex (3). The structures of the ligand and complex are characterized by elemental analysis, FT-IR, ¹H-, and ³¹P-NMR spectroscopy. Ru(II) complex has been employed as catalysts for the transfer hydrogenation of acetophenone in the presence of KOH using 2-propanol as a hydrogen source. The complex has demonstrated good catalytic activity in transfer hydrogenation of ketones.

Keywords:

• Cyclophosphazene
• Ru(II) complex
• catalyst
• catalytic activity