Transfer-hydrogenation catalytic

Catalytic transfer hydrogenation (entries 2 and 3 below) can be used to cleave benzyl esters in some compounds that contain sulfur, a poison for hydrogenolysis catalysts. 

HCO2NH4, have been used for catalytic transfer hydrogenation, which is in general a more rapid reaction than catalytic hydrogenation. 

In the sixth chapter the activation of O-H bonds of water, alcohols and carboxylic acids, and their addition to multiple bonds is reported. Since the formally oxidative addition of ROH gives rise to hydrido(hydroxo) complexes, [MH(OR)Ln] which are postulated as intermediates in many important reactions (water gas shift reaction, Wacker-chemistry, catalytic transfer hydrogenations etc.) the authors of this chapter,... 

Scheme 4.9 Catalytic transfer hydrogenations in PEC 200 under open-vessel conditions.

The concept of performing microwave synthesis in room temperature ionic liquids (RTIL) as reaction media has been applied to several different organic transformations (Scheme 4.18), such as 1,3-dipolar cycloaddition reactions [54], catalytic transfer hydrogenations [55], ring-closing metathesis [56], the conversion of alcohols to alkyl halides [57, 58], and several others [59-61],... 

Catalytic transfer hydrogenations for the reduction of carbon-carbon double bonds are illustrated in Scheme 4.18. Reductions of azide functionalities to amines with lipases suspended in organic media under microwave conditions have also been reported [206]. 

In MW-assisted chemistry reduction reactions were the last to appear on the scene the use of ammonium formate and catalytic transfer hydrogenation were initial examples [23 b]. 

CATALYTIC TRANSFER HYDROGENATION AND THE HYDROGENOLYTIC DEPROTECTION OF SULFUR-CONTAINING PEPTIDES... 

AE Jackson, RAW Johnstone. Rapid, selective removal of benzyloxycarbonyl groups from peptides by catalytic transfer hydrogenation. Synthesis 685, 1976. 

MK Anwer, RA Porter, AF Spatola. Applications of ammonium formate-catalytic transfer hydrogenation. Part V (1). Transfer hydrogenation of peptides containing p-chlorophcnyI al an i nc as a convenient method for preparation of deuterium labeled peptides. Int J Pept Prot Res 30, 489, 1987. 

Cleavage of benzyl ethers Benzyl ethers are cleaved in high yield by catalytic transfer hydrogenation with 20% palladium on carbon (1, 782)4 as catalyst and cyclohexcne as hydrogen donor. 

The effectiveness of catalytic transfer hydrogenation of nitroparaffins over MgO is demonstrated in the Table 4. At 450°C 1-nitropropane yielded 94.9 % of... 

In our previous paper (ref. 2) we demonstrated the particular role played by one-electron donor centres on magnesia surface in catalytic transfer hydrogenation. Moreover, nitroarenes exhibit high tendency to convert themselves into corresponding anion radicals during adsorption on MgO. Thus, it was expected that esr spectroscopy would reveal new data concerning the reactants activation. 

R.A.W. Johnstone, A.H. Wilby and I.D. Entwistle, Heterogeneous catalytic transfer hydrogenation and its relation to other methods for reduction of organic compounds, Chem. Rev., 85 (1985) 129-170. 

A further step towards optimised conditions in the catalytic transfer hydrogenation of alkenes was achieved with the introduction of the ionic liquid N-butyl-N -methylimidazolium hexafluorophosphate (BMIMPFg) as a solvent. The reduction of alkenes with formates and Pd/C in BMIMPF6 leads to saturated hydrocarbons in high yields. With an alkyne, a mixture of cis/trans alkenes and the saturated alkane was obtained (Scheme 4.5). Sufficiently pure products were isolated by a simple liquid-liquid... 

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