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Reactivity of BH3 and 9-BBN towards palladium(II) complexes of diphenylvinyl- and diphenylallyl-phosphine; X-ray structures of [PdCl2(PPh2CH2CH2CH3)]2 and [PdCl2(PPh2CH2CHCH2)]2

1999; Elsevier BV; Volume: 586; Issue: 2 Linguagem: Inglês

10.1016/s0022-328x(99)00283-1

1872-8561

Simon J. Coles, Paul Faulds, Michael B. Hursthouse, David G. Kelly, G. Ranger, Andrew J. Toner, Neil Walker,

Organoboron and organosilicon chemistry

Palladium(II) chloride complexes PdCl2L2 and [PdCl2L]2 have been prepared with the phosphine ligands PPh2CHCH2 and PPh2CH2CHCH2. The reactions of PdCl2L2 complexes with thf·BH3 afford equilibria in which the components may be identified by 31P{1H}-NMR spectroscopy. PdCl2L2 and [PdCl2L]2 complexes and phosphine–borane adducts are observed. In addition, analogues of the PdCl2L2 and [PdCl2L]2 complexes are present in which one or both phosphine ligands have undergone alkene hydroboration. The reaction of PdCl2(PhCN)2 and the cyclic adduct formed between 9-BBN and PPh2CH2CHCH2 [cyclo-(9-borabicyclo[3.3.1]nonanyl)-propyl(diphenyl)phosphine] has been studied. Opening of the P–B dative bond occurs with the formation of a [PdCl2L′]2 complex in which the phosphine ligand contains a pendant borane moiety. Hydrolysis in air yields the crystallographically characterised dimer [PdCl2(PPh2CH2CH2CH3)]2. The X-ray structure of the unsaturated analogue, [PdCl2(PPh2CH2CHCH2)]2, has also been obtained. Both compounds exist as symmetrical dimeric structures with terminal and asymmetric bridging halides.