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• 96-22-0 pentan-3-one 

Relevant academic research and scientific papers

Catalysts for hydrogenation and hydrosilylation, methods of making and using the same

A compound is provided including an organometallic complex represented by the formula I: [CpM(CO)2(NHC)Lk]+A???I wherein M is an atom of molybdenum or tangsten, Cp is substituted or unsubstituted cyclopentadienyl radical represented by the formula [C5Q1Q2Q3Q4Q5], wherein Q1to Q5are independently selected from the group consisting of H radical, C1-20hydrocarbyl radical, substituted hydrocarbyl radical, halogen radical, halogen-substituted hydrocarbyl radical, —OR, —C(O)R′, —CO2R′, —SiR′3and —NR′R″, wherein R′ and R″ are independently selected from the group consisting of H radical, C1-20hydrocarbyl radical, halogen radical, and halogen-substituted hydrocarbyl radical, wherein said Q1to Q5radicals are optionally linked to each other to form a stable bridging group, NHC is any N-heterocyclic carbene ligand, L is either any neutral electron donor ligand, wherein k is a number from 0 to 1 or L is an anionic ligand wherein k is 2, and A?is an anion. Processes using the organometallic complex as catalyst for hydrogenation of aldehydes and ketones are provided. Processes using the organometallic complex as catalyst for the hydrosilylation of aldehydes, ketones and esters are also provided.

Solvent-free ketone hydrogenations catalyzed by molybdenum complexes

Et2C=O is hydrogenated under solvent-free conditions using a catalyst prepared by hydride abstraction from HMo-(CO)2] η5:η1-C5H4(CH 2)2PCy2]; the catalyst functions at low catalyst loadings ( 0.4 mol%).

Catalytic ionic hydrogenations of ketones using molybdenum and tungsten complexes

Ketone complexes [CpM(CO)2(PR3)(η1-Et2C=O)] +BAr′4- (R = Ph or Me; M = Mo or W) were prepared from hydride transfer from Cp(CO)2(PR3)MH to Ph3C+BAr′4- [Ar′ = 3,5-bis(trifluoromethyl)phenyl] in the presence of (3-pentanone. These ketone complexes are catalyst precursors for hydrogenation of Et2C=O under mild conditions (23°C, 2). Analogous catalytic hydrogenations are obtained from reaction of the PCy3 complexes Cp(CO)2(PCy3)MH with Ph3C+BAr′4-. The proposed mechanism involves displacement of the ketone by H2, producing a cationic metal dihydride [CpM(CO)2(PR3)(H)2]+. Proton transfer from the dihydride gives a protonated ketone, followed by hydride transfer from the neutral metal hydride CpM(CO)2(PR3)H to produce the alcohol complex [CpM(CO)2(PR3)(Et2CHOH)]+. The free alcohol product is released from the metal through displacement by H2 or ketone, completing the catalytic cycle. In most cases, conversion of the ketone or alcohol complexes to the dihydride is the turnover-limiting step of the catalytic cycle, with ketone and alcohol complexes being observed during the reaction. For reactions using the W-PCy3 system, the dihydride [CpW(CO)2(PCy3)(H)2]+ is observed as the resting state of the catalytic process. Proton transfer is slow and becomes turnover-limiting in this case. The Mo catalysts are more active than W, and the dependence on phosphine is PCy3 > PPh3 > PMe3. The turnover rates are slow, with the fastest initial rate of about 2 turnovers per hour found for the Mo-PCy3 system. This ionic hydrogenation mechanism does not require coordination of the ketone to the metal for the hydrogenation, thus differing from traditional mechanisms where coordination of a ketone to a metal precedes insertion of the ketone into a M-H bond.