STEROIDS AND RELATED NATURAL PRODUCTS: XXXI. SELECTIVE REDUCTION OF ESTERS. PART B. CARBONATES

1966 ◽  
Vol 44 (11) ◽  
pp. 1293-1298
Author(s):  
George R. Pettit ◽  
William J. Evers
Keyword(s):  
Natural Products ◽  
Raney Nickel ◽  
Sodium Borohydride ◽  
Boron Trifluoride ◽  
Direct Reduction ◽  
Selective Reduction ◽  
Reduction Reaction

Direct reduction of several pivalate esters to neopentyl ethers has been accomplished with boron trifluoride – sodium borohydride. The utility of the reduction reaction was illustrated with esters Ic, IIb, and IVa. Under the same conditions, a selection (Id, IId, and IVa) of carbonate esters was found to be relatively resistant to reduction. In this respect, the carbonate esters resembled benzoate esters, and selective reduction of a ketone (IId) or another ester (IVa → IVb) in their presence was possible. For comparison, one xanthate ester (Ie) was allowed to react with boron trifluoride – sodium borohydride, and only the corresponding alcohol (Ia) was isolated. Raney nickel desulfurization of xanthate Ia was shown to provide alcohol Ia and hydrocarbon If as principal products.

STEROIDS AND RELATED NATURAL PRODUCTS: XXX. SELECTIVE REDUCTION OF ESTERS. PART A. BENZOATES

1966 ◽  
Vol 44 (11) ◽  
pp. 1283-1291
Author(s):  
George R. Pettit ◽  
Brian Green ◽  
George L. Dunn ◽  
Peter Hofer ◽  
William J. Evers
Keyword(s):  
Natural Products ◽  
Sodium Borohydride ◽  
Boron Trifluoride ◽  
Selective Reduction ◽  
Reaction Conditions ◽  
Benzyl Alcohols ◽  
Type Reaction ◽  
Aliphatic Esters ◽  
Favorable Reaction

Previously, reagents such as sodium borohydride – boron trifluoride were shown to be capable of reducing typical aliphatic esters and lactones to the corresponding ether derivatives. Under the same reaction conditions, a variety of benzoate esters (Ib, IIb, III, and V) were essentially unaffected. Resistance to attack was illustrated by conversion, with sodium borohydride – boron trifluoride, of 3-oxo-17β-benzoyloxy-5α-androstane (III) into 3β-hydroxy-17β-benzoyloxy-5α-androstane (IV) and of reserpine (V) into alcohol VI. With aryl–carbon–oxygen bonds of the ketone VII or alcohol IXa type, reaction with sodium borohydride– boron trifluoride was shown, in general, to cause reductive fission of the benzyl–oxygen linkage (e.g. X → XI). An exception was noted in the case of tertiary benzyl alcohols containing an available β-hydrogen (e.g. IXc). Here, dehydration to yield, for example, olefin XIIb appears to be the more favorable reaction course. The marked difference in the reactivity of sodium borohydride – boron trifluoride toward benzoyl–oxygen vs. benzyl–oxygen bonds has been demonstrated.

Rapid, efficient and selective reduction of aromatic nitro compounds with sodium borohydride and Raney nickel

2007 ◽  
Vol 274 (1-2) ◽  
pp. 202-207 ◽  
Author(s):  
Ivan Pogorelić ◽  
Mirela Filipan-Litvić ◽  
Sonja Merkaš ◽  
Goranka Ljubić ◽  
Ivica Cepanec ◽  
...  
Keyword(s):  
Raney Nickel ◽  
Sodium Borohydride ◽  
Selective Reduction ◽  
Nitro Compounds ◽  
Aromatic Nitro Compounds ◽  
Aromatic Nitro

Electro-catalysis of carbon black or titanium sub-oxide supported Pd–Gd towards formic acid electro-oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (73) ◽  
pp. 68989-68996 ◽  
Author(s):  
Nan He ◽  
Chuanguang Qin ◽  
Rumin Wang ◽  
Shuhui Ma ◽  
Yi Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Carbon Black ◽  
Formic Acid ◽  
Sodium Borohydride ◽  
Weight Percent ◽  
Reduction Reaction ◽  
Simultaneous Reduction ◽  
Electro Catalysis ◽  
Electro Oxidation ◽  
Supported Pd

Carbon black supported Pd–Gd catalysts (Pd–xGd/C, x is weight percent in catalyst) with different amounts of Gd were prepared by a simultaneous reduction reaction with sodium borohydride in aqueous solution.

DITHIOL-FERROUS CHLORIDE CATALYZED SELECTIVE REDUCTION OF ALKYNES WITH SODIUM BOROHYDRIDE

1985 ◽  
Vol 14 (12) ◽  
pp. 1851-1854 ◽  
Author(s):  
Masashi Kijima ◽  
Yoko Nambu ◽  
Takeshi Endo
Keyword(s):  
Sodium Borohydride ◽  
Selective Reduction ◽  
Ferrous Chloride

scholarly journals Supramolecular Tuning Enables Selective Oxygen Reduction Catalyzed by Cobalt Porphyrins for Direct Electrosynthesis of Hydrogen Peroxide

2019 ◽  
Author(s):  
Peter T. Smith ◽  
Younghoon Kim ◽  
Bahiru Punja Benke ◽  
Kimoon Kim ◽  
Christopher Chang
Keyword(s):  
Oxygen Reduction ◽  
High Selectivity ◽  
Selective Reduction ◽  
Design Strategy ◽  
Reduction Reaction ◽  
Site Isolation ◽  
Control Reaction ◽  
Electrosynthesis Of Hydrogen Peroxide ◽  
Cobalt Porphyrins ◽  
Catalytic Applications

<div> <div> <div> <p>We report a supramolecular design strategy for promoting the selective reduction of O2 for direct electrosynthesis of H2O2. Specifically, we utilized cobalt tetraphenylporphyrin (Co-TPP), a non-selective oxygen reduction reaction (ORR) catalyst, as a building block to assemble the permanently porous supramolecular cage Co-PB-1(6) bearing six Co-TPP subunits connected through twenty-four imine bonds. Reduction of these imine linkers to amines yields the more flexible porous cage Co-rPB-1(6). Both Co-PB-1(6) and Co-rPB-1(6) cages produce 90-100% H2O2 from electrochemical ORR catalysis in neutral pH water, and we attribute this high selectivity to site isolation of the discrete molecular units, as the analogous Co-TPP monomer generates only a 50% mixture of H2O2 and H2O from electrochemical ORR under the same conditions. The ability to control reaction selectivity in supramolecular structures beyond traditional host-guest interactions offers new opportunities for designing such architectures for a broader range of catalytic applications. </p> </div> </div> </div>

scholarly journals Tunable negative permittivity behavior and conductor–insulator transition in dual composites prepared by selective reduction reaction

2013 ◽  
Vol 1 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Zi-dong Zhang ◽  
Run-hua Fan ◽  
Zhi-cheng Shi ◽  
Shi-bing Pan ◽  
Ke-lan Yan ◽  
...  
Keyword(s):  
Selective Reduction ◽  
Reduction Reaction ◽  
Insulator Transition ◽  
Negative Permittivity

scholarly journals Oxygen Reduction Reaction on Metal and Nitrogen–Doped Carbon Electrocatalysts in the Presence of Sodium Borohydride

2020 ◽  
Vol 11 (4) ◽  
pp. 365-373 ◽  
Author(s):  
Ricardo Sgarbi ◽  
Edson A. Ticianelli ◽  
Frédéric Maillard ◽  
Frédéric Jaouen ◽  
Marian Chatenet
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Sodium Borohydride ◽  
Reduction Reaction ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon
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