Lee Kyung-Eun, Jeon Hyeong-Tak, Han Sam-Yong, Ham Jungyeob, Kim Yong-Joo, Lee Soon W
Department of Chemistry, Kangnung National University, Gangneung 210-702, Korea.
Dalton Trans. 2009 Sep 7(33):6578-92. doi: 10.1039/b907324h. Epub 2009 Jul 8.
Cyclopalladated azido dimers having various C,N-donor ligands, [Pd(mu-N3)(C,N-Ln)]2 (L1H = 2-(2'-thienyl)pyridine; L2H = azobenzene; L3H = 3,3'-dimethylazobenzene; L4H = N,N'-dimethylbenzylamine; L5H = 2-phenylpyridine), underwent cleavage with tertiary (or chelating) phosphines to form the cyclopalladated [Pd(N3)(PR3)(C,N-L)], the sigma-bonded [Pd(N3)(PR3)2(C-L)], or the dinuclear-cyclopalladated [PdN3(PR3)(C,N-L)]2(mu-P approximately P) complexes. In particular, treating [Pd(mu-N3)(C,N-L)]2 with the basic chelating phosphine (depe or dmpe) produced the homoleptic bis(chelating) complex [Pd(C,N-Ln)2] (n = 1-3). Complex [Pd(N3)(PR3)(C,N-L4)] or [Pd(N3)(PR3)2(C-L4)] reacted with aryl isocyanides to selectively give the imidoyl [Pd(N3)(-C=N-Ar)(PR3)(N-L4)] or the imidoyl carbodiimido complex [Pd(N=C=N-Ar)(-C=N-Ar)(PR3)(N-L4)], which was formed by the CN-Ar insertion into the orthometallated Pd-C bond on the phenyl moiety or the interaction into the Pd-N3 bond of the supporting ligand. In addition, reactions of [Pd(N3)(PR3)2(C-Ln)] (n = 1, 2, 4) with R-NCS {R = i-Pr, C6H4-NCS, (CH3)3Si} gave the S-coordinated tetrazole-thiolato Pd(II) complexes. Finally, the catalytic activity of the cyclopalladated azido complexes was evaluated.
具有各种C,N供体配体的环钯化叠氮二聚体[Pd(μ-N₃)(C,N-Ln)]₂(L₁H = 2-(2'-噻吩基)吡啶;L₂H = 偶氮苯;L₃H = 3,3'-二甲基偶氮苯;L₄H = N,N'-二甲基苄胺;L₅H = 2-苯基吡啶)与叔膦(或螯合膦)发生裂解反应,形成环钯化的[Pd(N₃)(PR₃)(C,N-L)]、σ键合的[Pd(N₃)(PR₃)₂(C-L)]或双核环钯化的[PdN₃(PR₃)(C,N-L)]₂(μ-P≈P)配合物。特别地,用碱性螯合膦(depe或dmpe)处理[Pd(μ-N₃)(C,N-L)]₂会生成均配型双(螯合)配合物[Pd(C,N-Ln)₂](n = 1 - 3)。配合物[Pd(N₃)(PR₃)(C,N-L₄)]或[Pd(N₃)(PR₃)₂(C-L₄)]与芳基异氰酸酯反应,选择性地生成亚胺酰基[Pd(N₃)(-C=N-Ar)(PR₃)(N-L₄)]或亚胺酰基碳二亚胺配合物[Pd(N=C=N-Ar)(-C=N-Ar)(PR₃)(N-L₄)],它们是通过CN-Ar插入苯基部分的邻位金属化Pd-C键或与支撑配体的Pd-N₃键相互作用而形成的。此外,[Pd(N₃)(PR₃)₂(C-Ln)](n = 1, 2, 4)与R-NCS{R = i-Pr, C₆H₄-NCS, (CH₃)₃Si}反应生成S配位的四唑硫醇钯(II)配合物。最后,评估了环钯化叠氮配合物的催化活性。