86319-87-1Relevant academic research and scientific papers
Parent-amido (NH2) palladium(II) complexes: Synthesis, reactions, and catalytic hydroamination
Kim, Youngwon,Park, Soonheum
, p. 614 - 629 (2016/06/01)
The treatment of [PdL3(NH3)](OTf)n (n = 1; L3 = (PEt3)2(Ph), (2,6-(Cy2PCH2)2C6H3), n = 2; L3 = (dppe)(NH3)) with NaNH2 in tetrahydrofuran at ambient temperature or -78 °C afforded the dimeric and monomeric parent-amido palladium(II) complexes anti-[Pd(PEt3)(Ph)(μ-NH2)]2 (1), [Pd(dppe)(μ-NH2)]2(OTf)2 (2), and Pd(2,6-(Cy2PCH2)2C6H3)(NH2) (3), respectively. The molecular structures of the amido-bridged (μ-NH2) dimeric complexes 1 and 2 were determined by single-crystal X-ray crystallography. The monomeric amido complex 3 reacted with trace amounts of water to give a hydroxo complex, Pd(2,6-(Cy2PCH2)2C6H3)(OH) (4). Exposing complex 3 to an excess of water resulted in the complete conversion of the complex into two species [Pd(2,6-(Cy2PCH2)2C6H3)(OH2)]+ and [Pd(2,6-(Cy2PCH2)2C6H3)(NH3)]+. Complex 3 reacted with diphenyliodonium triflate ([Ph2I]OTf) to give the aniline complex [Pd(2,6-(Cy2PCH2)2C6H3)(NH2Ph)]OTf. The reaction of 3 with phenylacetylene (HCCPh) yielded a palladium(II) acetylenide Pd(2,6-(Cy2PCH2)2C6H3)(CCPh) (5), quantitatively, along with the liberation of ammonia. The reaction of 3 with dialkyl acetylenedicarboxylate yielded diastereospecific palladium(II) vinyl derivatives (Z)-Pd(2,6-(Cy2PCH2)2C6H3)(CRCR(NH2)) (R = CO2Me (6a), CO2Et (6b)). The reaction of complexes 6a and 6b with p-nitrophenol produced Pd(2,6-(Cy2PCH2)2C6H3)(OC6H4-p-NO2) (7) and cis-CHRCR(NH2), exclusively. Reactions of 3 with either dialkyl maleate (cis-(CO2R)CHCH(CO2R)) (R = CH3, CH2CH3) or cis-stilbene (cis-CHPhCHPh) did not result in any addition product. Instead, isomerization of the cis-isomers to the trans-isomers occurred in the presence of catalytic amounts of 3. Complex 3 reacted with a stoichiometric amount of acrylonitrile (CH2CHCN) to generate a metastable insertion product, Pd(2,6-(Cy2PCH2)2C6H3)(CH(CN)CH2NH2). On the other hand, the reaction of 3 with an excess of acrylonitrile slowly produced polymeric species of acrylonitrile. The catalytic hydroamination of olefins with NH3 was examined in the presence of Pd(2,6-(Cy2PCH2)2C6H3)(OTf), producing a range of hydroaminated products of primary, secondary, and tertiary amines with different molar ratios of more than 99% overall yield. A mechanistic feature for the observed catalytic hydroamination is described with regard to the aminated derivatives of palladium(II).
Dimeric and monomeric palladium(II) parent-amido (NH2) complexes: Synthesis, characterization, and reactivity
Kim, Youngwon,Park, Soonheum
, p. 816 - 822 (2015/08/06)
The treatment of [PdL3(NH3)]OTf (L3Combining double low line(PEt3)2(Ph) (1), (2,6-(Cy2PCH2)2C6H3) (3)) with NaNH2 in THF afforded dimeric and monomeric parent-amido palladium(II) complexes with bridging and terminal NH2, respectively, anti-[Pd(PEt3)(Ph)(1/4-NH2)]2 (2) and Pd(2,6-(Cy2PCH2)2C6H3)(NH2) (4). The dimeric complex 2 crystallizes in the space group P21/n with aCombining double low line13.228(2) ?, bCombining double low line18.132(2) ?, cCombining double low line24.745(2) ?, βCombining double low line101.41(1)°, and ZCombining double low line4. It has been found that there are two crystallographically independent molecules with Pd(1)-Pd(2) and Pd(3)-Pd(4) distances of 2.9594 (10) and 2.9401(9) ?, respectively. The monomeric amido complex 4 protonates from trace amounts of water to give the cationic ammine species [Pd(2,6-(Cy2PCH2)2C6H3)(NH3)]+. Complex 4 reacts with diphenyliodonium triflate ([Ph2I]OTf) to give aniline complex [Pd(2,6-(Cy2PCH2)2C6H3)(NH2Ph)]OTf (5). Reaction of 4 with dialkyl acetylenedicarboxylate (DMAD, DEAD) yields diastereospecific palladium(II) vinyl derivative (Z)-(Pd(Cy2PCH2)2C6H3)(CRCombining double low lineCR(NH2)) (RCombining double low lineCO2Me (6a), CO2Et (6b)). Reacting complexes 6a and 6b with p-nitrophenol produces (Pd(Cy2PCH2)2C6H3)(OC6H4-p-NO2) (8) and cis-CHRCombining double low lineCR(NH2), exclusively.
