157801-59-7Relevant academic research and scientific papers
Synthesis of heterodinuclear hydride complexes by oxidative addition of a transition-metal hydride to Pt(0) and Pd(0) complexes
Komine, Nobuyuki,Kuramoto, Ayako,Yasuda, Toshiyuki,Kawabata, Tatsuya,Hirano, Masafumi,Komiya, Sanshiro
, p. 194 - 205 (2015/08/18)
Abstract Heterodinuclear hydridoplatinum and -palladium complexes, (dppe)HPt-MLn (MLn = MoCp(CO)3 (3a), WCp(CO)3 (3b)), (dppe)Pt(μ-H)(μ-CO)Mn(CO)4 (3c), (dppe)Pt(μ-H)(μ-CO)FeCp(CO) (3d), cis-L′2HPt-MLn (5aa: LE' = PPh3; MLn = MoCp(CO)3, 5ba: LE' = PPh3; MLn = WCp(CO)3, 5ab: LE' = PMePh2; MLn = MoCp(CO)3, 5ac: LE' = PMe2Ph; MLn = MoCp(CO)3), (dppe)Pd(μ-H)(μ-CO)MLn (MLn = MoCp(CO)2 (7a), WCp(CO)2 (7b)), (dppe)Pd(μ-H)(μ-CO)Mn(CO)4 (7c) are prepared by the oxidative addition of mononuclear transition-metal hydride complexes to zero-valent platinum or palladium complexes. The reactions of the heterodinuclear hydride complexes 3a, 3d and 7a with electron deficient alkenes and alkynes such as dimethyl fumarate or DMAD cause reductive elimination at the Pt or Pd center to give the Pt(alkene or alkyne)(dppe) and MHLn,, suggesting reversibility of this process. The DFT calculations suggest that these reactions are controlled by the thermodynamic stability and the electron rich alkene complex of Pt(0) (or Pd(0)) are preferable to prepare these heterodinuclear hydride complexes by the oxidative addition.
Platinum-catalyzed acrylonitrile hydrophosphination. P-C bond formation via olefin insertion into a Pt-P bond
Wicht, Denyce K.,Kourkine, Igor V.,Kovacik, Ivan,Glueck, David S.,Concolino, Thomas E.,Yap, Glenn P. A.,Incarvito, Christopher D.,Rheingold, Arnold L.
, p. 5381 - 5394 (2008/10/08)
The acrylonitrile complexes Pt(diphos)(CH2CHCN) (diphos = dppe (1), dcpe (2); dppe = Ph2PCH2CH2PPh2, dcpe = Cy2PCH2CH2PCy2, Cy = cyclo-C6H11) are catalyst precursors and, for some substrates, resting states, during addition of P-H bonds in primary and secondary phosphines across the C=C double bond of acrylonitrile (hydrophosphination). Oxidative addition of P-H bonds to related catalyst precursors gives the phosphido hydride complexes Pt(diphos)(PRR′)(H) (diphos = dppe, R = H, R′ = Mes* (20), R = R′ = Mes (21); diphos = dcpe, R = H, R′ = Mes* (22); Mes = 2,4,6-Me3C6H2, Mes* = 2,4,6-(t-Bu)3C6H2). Acrylonitrile does not insert into the Pt-H bond of these hydrides to give cyanoethyl ligands; the putative products, the phosphido complexes Pt(diphos)(CH2CH2CN)(PRR′) (diphos = dppe, R = H, R′ = Mes* (9), R = R′ = Mes (10); diphos = dcpe, R = H, R′ = Mes* (11)) were prepared independently and found to be stable to P-C reductive elimination. Instead, catalysis appears to occur by selective insertion of acrylonitrile into the Pt-P bond to yield the alkyl hydrides Pt(diphos)[CH(CN)CH2PRR′](H), followed by C-H reductive elimination and regeneration of 1 or 2. This insertion was observed directly in model methyl phosphido complexes M(dppe)-(Me)(PRR′) (M = Pt, R = H, R′ = Mes* (12), R = R′ = Mes (13); M = Pd, R = H, R′ = Mes* (17)), yielding M(dppe)[CH(CN)CH2PRR′](Me), (14, 15, 18). Similarly, treatment of Pt(dcpe)-(PHMes*)(H) (22) with acrylonitrile gives Pt(dcpe)[CH(CN)CH2PHMes*](H) (24) as a mixture of diastereomers; the isomeric Pt(dcpe)[PMes*(CH2CH2CN)](H) (25), which was prepared independently, was also observed during this reaction. Both 24 and 25 decompose in the presence of acrylonitrile to form Pt(dcpe)(CH2CHCN) (2) and PHMes*(CH2CH2CN) (3a). The C-H reductive elimination step was modeled by studies of Pt(dcpe)[CH(Me)(CN)](H) (26). Another isomer, Pt(dcpe)[CH(Me)(CN)](PHMes*) (29), which formally results from insertion of acrylonitrile into the Pt-H bond of 22, was formed by decomposition of complex 2 during catalysis. Complex 29 is inactive in catalysis but decomposes to partially regenerate the active catalyst 2. The cyanoethyl compounds Pt(dcpe)(CH2CH2CN)(PHMes*) (11), trans-Pt-(PPh3)2(CH2CH2CN)(Br), and PMeS2(CH2CH2CN) (23) were structurally characterized by X-ray crystallography.
Synthesis and reactivity of platinum-containing heterodinuclear complexes with methyl and 1,2-bis(diphenylphosphino)ethane ligands. X-Ray crystal structure of (dpe)MePt-FeCp(CO)2*THF
Fukuoka, Atsushi,Sadashima, Takanori,Sugiura, Takeshi,Wu, Xiaosong,Mizuho, Yuji,Komiya, Sanshiro
, p. 139 - 148 (2007/10/02)
New-platinum-containing heterodinuclear complexes with methyl and 1,2-bis(diphenylphosphino)ethane (dpe) ligands have been prepared by metathetical reactions of PtMe(NO3)(dpe) with Na: MLn = MoCp(CO)3 (1); WCp(CO)3 (2); Mn(CO)5 (3); FeCp(CO)2 (4); Co(CO)4 (5).The molecular structure of (dpe)MePt-FeCp(CO)2*THF (4*THF) has been determined by X-ray crystallography: the geometry at Pt is square planar and the FeCp(CO)2 moiety has a piano-stool type structure.Thermolysis of 4 in C6D6 at 70 deg C for 2 h gives MeFeCp(CO)2 (8) in 30percent yield, but other dinuclear complexes are thermally stable under these conditions.Methyl migration to produce 8 was accelerated by the addition of electron-deficient olefins such as acrylonitrile and fumaronitrile.From the kinetic study, a mechanism involving two pathways is proposed: one is direct thermolysis from 4 to 8, while the other is the associative reductive elimination of 8 from the olefin-coordinated intermediate 9. Key words: Molybdenum; Platinum; Heterobimetallics; Iron; Tungsten; Manganese; Cobalt
