97295-82-4Relevant academic research and scientific papers
Synthesis and reactivity of a platinum(II) complex with a chelating dehydro(arylboronic anhydride) ligand. Transmetalation of arylboronic acid
Pantcheva, Ivayla,Osakada, Kohtaro
, p. 1735 - 1741 (2008/10/09)
The reaction of ArB(OH)2 (Ar = C6H4OMe-4, Ph, C6H4COMe-4) with PtI2(dppe) in THF in the presence of Ag2O and H2O at room temperature produced a Pt complex with a chelating dehydro(arylboronic anhydride) ligand, Pt(OBArOBArO)(dppe) (1a, Ar = C6H4OMe-4; 1b, Ar = Ph; 1c, Ar = C6H4COMe-4). The complexes were characterized by NMR spectroscopy and X-ray crystallography. Reactions of protonic acids, such as HCl, CF3COOH, and CH3COOH, with 1a yielded complexes with chloro and carboxylate ligands, PtX2(dppe) (2, X = Cl; 3, X = OCOCF3; 4, X = OCOMe). The complexes 1a - c react with arylboronic acids bearing the same aryl group as the ligands of the complexes to form diarylplatinum complexes, PtAr2(dppe) (5a, Ar = C6H 4OMe-4; 5b, Ar = Ph; 5c, Ar = C6H4COMe-4), respectively. Reactions of 4-MeCOC6H4B(OH)2 with Ib and of PhB(OH)2 with 1c in 2:1 molar ratios form mixtures of three diarylplatinum complexes in a statistical ratio.
β-Hydride Elimination from Methoxo vs. Ethyl Ligands: Thermolysis of (DPPE)Pt(OCH3)2, (DPPE)Pt(CH2CH3)(OCH3) and (DPPE)Pt(CH2CH3)2
Bryndza, Henry E.,Calabrese, Joseph C.,Marsi, Marianne,Roe, D. Christopher,Tam, Wilson,Bercaw, John E.
, p. 4805 - 4813 (2007/10/02)
Thermolysis of (DPPE)Pt(OCH3)2 (1) (DPPE=1,2-bis(diphenylphosphino)ethane, (C6H5)2PCH2CH2P(C6H5)2) at 25 deg C leads to a mixture of methanol, formaldehyde oligomers, and small amounts of carbon monoxide (CO).Kinetics experiments, labeling studies, and solvent effects suggest this decomposition proceeds by initial preequilibrium β-hydride migration to the metal followed by rate-limiting release of organic products.While 1 decomposes at 25 deg C and (DPPE)Pt(CH2CH3)2 only slowly releases ethylene and ethane at 160 deg C, (DPPE)Pt(CH2CH3)(OCH3) (3) decomposes to a mixture of ethylene, ethane, methanol, and formaldehyde oligomers at 100 deg C.The predominance of ethylene over ethane suggests thermolysis proceeding by β-elimination from the ethyl ligand is energetically easier than the comparable process from the methoxo ligand by 0.3 kcal/mol.Labeling studies confirm the preequilibrium nature of this β-elimination.The relative M-C vs.M-O bond strengths are discussed in light of this information.
Mechanism of CO insertion into metal-oxygen bonds. Reaction of (DPPE)Pt(OCH3)R (R = CH3 or OCH3) with CO
Bryndza, Henry E.
, p. 1686 - 1687 (2008/10/08)
The carbonylation of (DPPE)PtCH3(OCH3), 1 (DPPE = 1,2-bis(diphenylphosphino)ethane, (C6H5)2PCH2CH2P(C 6H5)2), to yield (DPPE)PtCH3(CO2CH3) is first order in 1 and first order in CO. Low-temperature 13C NMR experiments suggest formation of a five-coordinate CO complex intermediate, and crossover experiments rule out the involvement of dissociated species during this reaction. Similar complex 3, (DPPE)Pt(OCH3)2, carbonylates stepwise through (DPPE)Pt(OCH3)(CO2CH3) to ultimately form (DPPE)Pt(CO2CH3)2. Similar kinetics and alcohol exchange reactions suggest the carbonylation mechanism is the same one outlined for the methyl methoxide. Low-temperature 13C NMR measurements permit observation and quantification of a five-coordinate CO adduct.
Syntesis and Reactivity od (dppe)Pt(OMe)2
Bryndza, Henry E.,Kretchmar, Suzanne A.,Tulip, Thomas H.
, p. 977 - 978 (2007/10/02)
Synthesis of (dppe)Pt(OMe)2 (1) by NaOMe metathesis on the analogous dichloride is reported along with the thermal and carbonylation chemistry of (1); the release of dimethyl carbonate and dimethyl oxalate from th
