6533b871fe1ef96bd12d0ee9

RESEARCH PRODUCT

Insertion of One, Two, and Three Molecules of Alkyne into the Pd−C Bond of Ortho-palladated Primary and Secondary Arylalkylamines

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The ortho-metalated complex [Pd2{κ2(C,N)-C6H4CH2CH2NHMe-2}2(μ-Br)2] (1) can be prepared by refluxing a 1:1 mixture of Pd(OAc)2 and N-methylphenethylamine in acetonitrile, followed by addition of an excess of NaBr. Complex 1 reacts with PPh3 to give the mononuclear derivative [Pd{κ2(C,N)-C6H4CH2CH2NHMe-2}Br(PPh3)] (2). The cationic complex [Pd{κ2(C,N)-C6H4CH2CH2NHMe-2}(py)2]ClO4 (3) can be obtained by reacting 1 with AgClO4 and pyridine. The previously reported complex [Pd2{κ2(C,N)-C6H4CH2NHCH2Ph-2}2(μ-Br)2] (A) reacts with PhC≡CCO2R (R = Me, Et) to give the monoinserted derivatives [Pd2{κ2(C,N)-C(Ph)═C(CO2R)C6H4CH2NHCH2Ph-2}2(μ-Br)2] (R = Me (4a), Et (4b)). These dimers react with neutral ligands (L = PPh3, tBuNC) in a 2:1 molar ratio to afford the monomeric complexes [Pd{κ2(C,N)-C(Ph)═C(CO2R)C6H4CH2NHCH2Ph-2}Br(L)] (L = PPh3, R = Me (5a), Et (5b); L = tBuNC, R = Me (6a), Et (6b)). The complexes [Pd2{κ2(C,N)-C6H3CH2NH2-2,X-5}2(μ-Br)2] (X = Cl (C), F (D), NO2 (E)) react with RC≡CR (R = Et, Ph) to give [Pd{...