ORGANOMETALLIC CHEMISTRY OF DIPHOSPHAZANES .13. PALLADIUM COMPLEXES OF UNSYMMETRICAL DIPHOSPHAZANES PH(2)PN(PR-I)PYY'

Unsymmetrical diphosphazanes Ph(2)PN(Pr-i)PYY' [YY' = O2C12H8 (L(1)), O2C20H12 (L(2)); Y = Ph and Y' = OC6H4Br-4 (L(3)), OC(6)H(4)Me-4 (L(4) ), OC(6)H(3)Me(2)-3,5 (L(5)), N(2)C(3)HMe(2)-3,5 (L(6))] react with ci s-[PdCl2(COD)] (COD = cycloocta-1,5-diene) giving the chelate complexe s of the type cis-[PdCl2{eta(2)-Ph(2)PN(Pr-i)PYY'}] [YY' = O2C12H8 (1) , O2C20H12 (2), Y = Ph and Y' = OC6H4Br-4 (3), OC(6)H(4)Me-4 (4), OC(6 )H(3)Me(2)-3,5 (5), N(2)C(3)HMe(2)-3,5 (6)]. The P-N bond in 3 and 5 u ndergoes a facile cleavage in methanol solution to give -[PdCl2{eta(1) Ph(2)P(OMe)}{eta(1)-PhP(NHPri)(Y')}] [Y' = OC6H4Br-4 (7), OC(6)H(3)Me( 2)-3,5 (8)]. Reactions of Pd-2(dba)(3) . CHCl3 (dba = dibenzylideneace tone) with the diphosphazanes Ph(2)PN(Pr-i)PPhY' [Y' = OC(6)H(4)Me-4 ( L(4)), N(2)C(3)HMe(2)-3,5 (L(6)), N2C3H3 (L(7))] in the presence of Me I yields cis-[PdI2{eta(2)-Ph(2)PN(Pr-i)PPhMe}] (9); the P-O or P-N(pyr azolyl) bond of the starting ligands is cleaved and a p-C(Me) bond is formed. An analogous oxidative addition reaction in the presence of Ph (2)PN(Pr-i)PPh(2) (L(8)) yields cis-[PdI(Me)(eta(2)-L(8))] (10) and ci s-[PdI2(eta 2-L(8))] (11). The structures of 8 and 9 have been determi ned by X-ray diffraction. Copyright (C) 1996 Elsevier Science Ltd