Bis(allyl)ruthenium(IV) Complexes Containing Water-Soluble Phosphane Ligands: Synthesis, Structure, and Application as Catalysts in the Selective Hydration of Organonitriles into Amides

The novel mononuclear ruthenium(IV) complexes [RuCl2(eta(3) eta(3)- C10H16)(L)] [L=(meta-sultonatophenyl)diphenylphosphane sodium salt (TPPMS) (2a), 1,3,5-triaza-7-phosphatricyclo[3 3 1 1(3) (7)]decane (PTA) (2b), 1-benzyl-3,5-diaza-1-azonia-7-phosphatricyclo[3 3 1 1(3) (7)]decane chloride (PTA-Bn) (2c), 3,7-diacetyl-1.3.7-triaza-5-phosphabicyclo[3 3 1]nonane (DAPTA) (2d), and 2.4.10-trimethyl-1.2.4.5.7.10-hexaaza-3-phosphatricyclo[3 3 1.1(3.7)]decane (TNPA) (2e)] have been synthesized by treatment of the dimeric precursor [{RuCl(mu Cl)(eta(3 center dot)eta(3)-C10H16)}(2)] (C10H16=2.7-dimethylocta-2.6-diene-1.8-diyl) (1) with two equivalents of the corresponding water-soluble phosphane Reaction of 1 with one equivalent of the cage-type diphosphane ligand 2,3,5.6,7.8-hexamethyl-2.3,5.6.7.8-hexaaza-1,4- diphosphabicyclo[ 2 2 2]octane (THDP) allowed also the high-yield preparation of the dinuclear derivative [{RuCl2(eta(3) eta(3)-C10H16)}(2)(mu-THDP)] (2F) All these new complexes have been analytically and spectroscopically (IR and multinuclear NMR) characterized In addition, the structure of 21), 2c, 2d, and 21 was unequivocally confirmed by X-ray diffraction methods Complexes 2a-f are active catalysts for the selective hydration of nitriles to amides in pure aqueous medium under neutral conditions The wide scope of this catalytic transformation has been evaluated by using the most active catalysts [RuCl2(eta(3) eta(3)-C10H16)(THPA)] (2e) and [{RuCl2(eta(3 center dot)eta(3)-C10H16)}(2),(mu-THDP)] (2f) Advantages of using MW versus Conventional thermal heating are also discussed