Convenient synthesis of new binucleating ligands derived from 1,3-diacetylbenzene. Possible precursors for oligomeric organometallic materials
1991; Elsevier BV; Volume: 10; Issue: 13 Linguagem: Inglês
10.1016/s0277-5387(00)86075-1
ISSN1873-3719
AutoresDominique Matt, Alain Van Dorsselaer,
Tópico(s)Asymmetric Hydrogenation and Catalysis
ResumoBis-phosphine 1,3-bis(diphenylphosphinoacetyl)benzene (LH2) is obtained in high yield by reacting Ph2PCl with bis(lithium anolate) derived from 1,3-diacetylbenzene in tetrahydrofuran. Its oxidation by air gives quantitatively the corresponding double β-ketophosphine oxide. The ligand LH2 reacts with [(o-C6H4CH2NMe2)PdCl]2 to give the binuclear complex [{(o-C6H4CH2NMe2)PdCl}2(μ-LH2)] in which the bis-phosphine behaves as a bridging ligand. The latter complex is conveniently converted by prolonged treatment with sodium hydride in tetrahydrofuran into the bis-enolato complex [{(o-C6H4CH2NMe2)Pd}2(μ-L)] in which the bridging ligand L contains two chelating subunits. Reaction of LH2 with [Pd(acac)2] leads to oligomeric material of formula (PdL)n. Mass spectroscopic measurements suggest the presence of a tetrameric species, (PdL)4, present in the reaction mixture.
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