Selective dehydrogenation of alcohols and diols catalyzed by a dihydrido iridium PCP pincer complex

2001 ◽  
Vol 79 (5-6) ◽  
pp. 823-829 ◽  
Author(s):  
David Morales-Morales ◽  
Rocío Redón ◽  
Zhaohui Wang ◽  
Do W Lee ◽  
Cathleen Yung ◽  
...  
Keyword(s):  
Carbonyl Complex ◽  
Secondary Alcohols ◽  
Preparative Scale ◽  
Pincer Complex ◽  
Alcohol Dehydrogenation ◽  
Dehydrogenation Reactions ◽  
Pcp Pincer

The PCP pincer complex, IrH2{C6H3-2,6-(CH2P-t-Bu2)2} (1) catalyzes the transfer dehydrogenation of primary and secondary alcohols. Dehydrogenation occurs across the C—O bond rather than the C—C bonds and the corresponding aldehydes or ketones are obtained as the sole products arising from the dehydrogenation reactions. Methanol is an exception to this pattern of reactivity and undergoes only stoichiometric dehydrogenation with 1 to give the carbonyl complex, Ir(CO){C6H3-2,6-(CH2P-t-Bu2)2} (2). The products are obtained in nearly quantitative yields when the reactions are carried out in toluene solutions. Under the same conditions, 2,5-hexanediol is converted to the annulated product, 3-methyl-2-cyclopenten-1-one which has been isolated in 91% yield in a preparative scale reaction.Key words: alcohol, dehydrogenation, ketones, iridium pincer complex, annulation.

Reversible Ligand Protonation of a Mn(I) PCP Pincer Complex To Afford a Complex with an η2-Caryl–H Agostic Bond

2018 ◽  
Vol 37 (20) ◽  
pp. 3475-3479 ◽  
Author(s):  
Daniel Himmelbauer ◽  
Berthold Stöger ◽  
Luis F. Veiros ◽  
Karl Kirchner
Keyword(s):  
Pincer Complex ◽  
Pcp Pincer

High yield thiolation of iodobenzene catalyzed by the phosphinite nickel PCP pincer complex: [NiCl{C6H3-2,6-(OPPh2)2}]

2006 ◽  
Vol 47 (29) ◽  
pp. 5059-5062 ◽  
Author(s):  
Valente Gómez-Benítez ◽  
Oscar Baldovino-Pantaleón ◽  
Cesar Herrera-Álvarez ◽  
Rubén A. Toscano ◽  
David Morales-Morales
Keyword(s):  
High Yield ◽  
Pincer Complex ◽  
Pcp Pincer

scholarly journals An electron poor iridium pincer complex for catalytic alkane dehydrogenation

2016 ◽  
Vol 45 (40) ◽  
pp. 15963-15969 ◽  
Author(s):  
Oleksandr O. Kovalenko ◽  
Ola F. Wendt
Keyword(s):  
Iridium Complex ◽  
Alkane Dehydrogenation ◽  
Pincer Complex ◽  
Dehydrogenation Reactions

A new electron deficient iridium complex demonstrates an improved TON in alkane transfer dehydrogenation reactions compared to similar pre-catalysts.

Benzo annulated cycloheptatriene PCP pincer iridium complexes

2014 ◽  
Vol 43 (32) ◽  
pp. 12187-12199 ◽  
Author(s):  
Wolfgang Leis ◽  
Sophie Wernitz ◽  
Benedikt Reichart ◽  
David Ruckerbauer ◽  
Johannes Wolfram Wielandt ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Iridium Complexes ◽  
Pincer Complex ◽  
Pcp Pincer

Chemical conversions of a cycloheptatriene iridium pincer complex were studied by NMR and MS techniques as well as DFT calculations.

Synthesis of a Water-Soluble Ruthenium Complex and Its Catalytic Activity for Acceptorless Alcohol Dehydrogenation in Aqueous Medium

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1644-1648 ◽  
Author(s):  
Senthilkumar Muthaiah ◽  
Anita Bhatia
Keyword(s):  
Catalytic Activity ◽  
Aqueous Medium ◽  
Ruthenium Complex ◽  
Water Soluble ◽  
Catalytic Cycle ◽  
Secondary Alcohols ◽  
Atom Economy ◽  
Hydrogen Acceptor ◽  
Alcohol Dehydrogenation ◽  
Acceptorless Alcohol Dehydrogenation

The synthesis of a ruthenium complex bearing a PN-chelating ligand is described. The complex, in the presence of KOH, enabled the synthesis of ketones from secondary alcohols in the absence of a hydrogen acceptor in aqueous medium. This synthetic protocol, which uses water as the medium, is green and has a high atom economy as it avoids the use of an acceptor and produces hydrogen as the sole ­byproduct. Mechanistic investigations revealed that the catalytic cycle involves a phosphine dissociative pathway.

Improved synthesis of Bn5CpRu(CO)2Cl and its application as racemization catalyst in preparative-scale metalloenzymatic dynamic kinetic resolution of 1-phenylethanol

2010 ◽  
Vol 83 (3) ◽  
pp. 479-487 ◽  
Author(s):  
Denys Mavrynsky ◽  
Liisa T. Kanerva ◽  
Reijo Sillanpää ◽  
Reko Leino
Keyword(s):  
Kinetic Resolution ◽  
Immobilized Enzyme ◽  
Metal Catalyst ◽  
Secondary Alcohols ◽  
Mass Loading ◽  
Dynamic Kinetic Resolution ◽  
Preparative Scale ◽  
Highly Active ◽  
Complex Forms

An improved gram-scale synthesis of Bn5CpRu(CO)2Cl is reported based on heating of pentabenzylcyclopentadiene with Ru3(CO)12 at 160 °C under argon atmosphere in mesitylene followed by addition of chloroform, continued heating, and evaporation of the solvents. Subsequent washing of unreacted ligand precursor with hexane provided pure title compound in 77 % yield. In combination with Candida antarctica lipase B (CAL-B) (Novozym 435), this complex forms a highly active racemization catalyst for metallo-enzymatic dynamic kinetic resolution (DKR) of secondary alcohols as demonstrated in the present work by converting 100 g of racemic 1-phenylethanol to (R)-1-phenylethanol in >99 % ee and 93 % overall yield over two steps using 0.05 mol % loading of the metal catalyst and 1 mass % loading of immobilized enzyme. In addition, the synthesis and crystallographic characterization of the palladium congener Bn5CpPd(PPh3)Cl are briefly discussed.

A Practical Synthesis of Ammonia from Nitrogen Gas, Samarium Diiodide and Water Catalyzed by a Molybdenum–PCP Pincer Complex

Synthesis ◽  
2019 ◽  
Vol 51 (20) ◽  
pp. 3792-3795 ◽  
Author(s):  
Yuya Ashida ◽  
Shoichi Kondo ◽  
Kazuya Arashiba ◽  
Takamasa Kikuchi ◽  
Kazunari Nakajima ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Catalytic Amount ◽  
Practical Method ◽  
Samarium Diiodide ◽  
Ambient Conditions ◽  
Nitrogen Gas ◽  
Pincer Complex ◽  
Proton Source ◽  
Practical Synthesis ◽  
Pcp Pincer

A practical method for ammonia synthesis is described. The reaction of atmospheric pressure of nitrogen gas with samarium diiodide as a reducing reagent and water as a proton source in the presence of a catalytic amount of a molybdenum trichloride complex bearing a PCP [1,3-bis(di-tert-butylphosphinomethyl)benzimidazol-2-ylidene]-type pincer ligand occurs under ambient conditions to afford ammonium sulfate after treatment with sulfuric acid.

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