Bisamino(diphosphonite) with dangling olefin functionalities: synthesis, metal chemistry and catalytic utility of Rh-I and Pd-II complexes in hydroformylation and Suzuki-Miyaura reactions

Bisamino(diphosphonite), p-C6H4{N{P(OC6H4C3H5-o)(2)}(2)}(2) (1), was prepared by reacting p-C6H4{N(PCl2)(2)}(2) with four equivalents of o-allylphenol in 85% yield. Compound 1 on treatment with [M(CO)(4)(HNC5H10)(2)] (M = Mo or W) gave cis-[{M(CO)(4)}(2){p-C6H4{N(P(OC6H4C3H5-o)(2))(2)}(2)}] (2, M = Mo; 3, M = W). The reaction of 1 with [Fe(eta(5)-C5H5)(CO)(2)](2) yielded the complex [{Fe(eta(5)-C5H5)(mu-CO)}(2){p-C6H4{N(P-(OC6H4C3H5-o)(2))(2)}(2)}] (4). Treatment of 1 with Fe(CO)(5) furnished a mononuclear complex, [{Fe(CO)(3)}(2)-{p-C6H4{N{P(OC6H4C3H5-o)(2)}(2)}(2)}] (5). The ruthenium(II) complex, [{(eta(6)-p-cymene)Ru(mu-Cl)(3)RuCl}(2){p-C6H4-{N(P(OC6H4C3H5-o)(2))(2)}(2)}] (6), was obtained on treatment of ligand 1 with [(eta(6)-p-cymene)Ru(Cl)(2)](2). The reaction between 1 and [Rh(COD) Cl](2) (COD = 1,5-cyclooctadiene) in dichloromethane resulted in the formation of a dinuclear complex [{RhCl}(2){p-C6H4{N(P(OC6H4C3H5-o)(2))(2)}(2)}] (7), in which the allyl double bond of one of the phenoxy groups coordinates to the metal center. When ligand 1 was reacted with two equivalents of [Pd(COD)Cl-2], a dinuclear complex [{PdCl2}(2)-{p-C6H4{N(P(OC6H4C3H5-o)(2))(2)}(2)}] (8) was obtained. With copper(I) halides, ligand 1 afforded tetranuclear complexes, [{(Cu(mu-X)(NCCH3))(2)}(2)-{p-C6H4{N(P(OC6H4C3H5-o)(2))(2)}(2)}] (9, X = Cl; 10, X = Br; 11, X = I). Reaction of 1 with four equivalents of [AuCl(SMe2)] produced a tetranuclear complex, [(AuCl)(4){p-C6H4{N{P(OC6H4C3H5-o)(2)}(2)}(2)}] (12). Complex 8 shows excellent catalytic activity in the Suzuki-Miyaura cross-coupling reaction under microwave conditions and complex 7 catalyzes hydroformylation of styrenes with good TONs.