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Sodium hydrogen telluride reduction

On the other hand, the triflate 254 was treated with sodium azide, followed by reduction of the lactone carbonyl function, and subsequent mesylation, complete removal of the protecting groups and reprotection by EtsSiCl, to afford 259 (Scheme 25). Sodium hydrogen telluride reduction of the azide function in 259 followed by intramolecular double cyclization with sodium acetate afforded the bicycle 260, which on deprotection furnished 261 in 45% overall yield from the triflate 254. [Pg.264]

When the conditions are controlled properly, Zn can mediate the reduction of the C-C double bond of a, (3-unsaturated carbonyl compounds in the presence of a nickel catalyst in aqueous ammonium chloride (Eq. 10.7). The use of ultrasonication enhances the rate of the reaction.15 Sodium hydrogen telluride, (NaTeH), prepared in situ from the reaction of... [Pg.315]

Sodium hydrogen telluride is prepared by reduction of tellurium with NaBH4 under several conditions. The original procedure uses ethanol as the solvent, adding, after complete reduction of the tellurium, an appropriate amount of acetic acid (see Section 4.1.2, ref. 10 Section 4.1.7, ref. 29). [Pg.6]

In addition to the described reduction of double bonds conjugated to a carbonyl group, sodium hydrogen telluride and phenyltellurol reduce double (and triple) bonds conjugated to aromatic systems. " ... [Pg.119]

Hydrogen telluride, sodium hydrogen telluride as well as phenyltelluroP afford the reduction of imines to secondary amines. [Pg.120]

In the reduction of imines and enamines with hydrogen telluride and sodium hydrogen telluride, hydrolysis leading to primary amines and carbonyl compounds is frequently competitive with the reduction. This undesired side reaction is minimized by the addition of triethylamine, in the case of hydrogen telluride. ... [Pg.120]

Control of the pH to within the 6-7 range has been shown to be important in the reduction of imines with sodium hydrogen telluride. At a higher pH (10-11) no reduction occurs. ... [Pg.120]

The reduction of nitro- and dinitroalkanes with sodium hydrogen telluride gives, respectively, diazenes (dimers of nitrosoalkenes) and olefins.- ... [Pg.122]

The reduction of azo compounds to hydrazo compounds is also achieved by means of aryltellurols or sodium hydrogen telluride. The last reagent (generated from NaBH4 and... [Pg.125]

Reductive opening of oxiranes with sodium hydrogen telluride and sodium telluride... [Pg.129]

Under appropriate experimental conditions, hydrogen telluride, phenyl tellurol, and sodium hydrogen telluride perform the selective reduction of double bonds of a,/3-unsaturated carbonyl systems.89 90 This reaction with a,j3-unsaturated ketones complements the cerium trichloride/sodium borohydride method, which reduces the carbonyl group, keeping the carbon-carbon double bond intact92 (Scheme 18). [Pg.598]

The reaction of nitroalkanes and dinitroalkanes with sodium hydrogen telluride gives nitrosoalkane dimers and olefins, respectively.96 The reduction of other nitrogenated species such as hydroxylamines, azides, nitroso, azo, and azoxy compounds can also be performed by using tellurium reagents.6,11,12... [Pg.599]

Reductive alkylations of amines with carbonyl compounds can be also accomplished quantitatively by means of selenophenol (PhSeH) at room temperature in chloroform198 and by sodium hydrogen telluride (NaHTe) in ethanol at room temperature199. [Pg.981]

REDUCTION, REAGENTS Bis(N-methylpi-perazinyl)aluminum hydride. Borane-Di-methyl sulfide. Borane-Tetrahydrofurane. Borane-Pyridine. n-Butyllithium-Diisobu-tylaluminum hydride. Calcium-Amines. Diisobutylaluminum hydride. 8-Hydroxy-quinolinedihydroboronite. Lithium aluminum hydride. Lithium 9-boratabicy-clo[3.3.1]nonane. Lithium n-butyldiisopro-pylaluminum hydride. Lithium tri-j c-butylborohydride. Lithium triethylborohy-dride. Monochloroalane. Nickel boride. 2-Phenylbenzothiazoline. Potassium 9-(2,3-dimethyl-2-butoxy)-9-boratabicy-clo[3.3.1]nonane. Raney nickel. Sodium bis(2-methoxyethoxy)aluminum hydride. Sodium borohydride. Sodium borohy-dride-Nickel chloride. Sodium borohy-dride-Praeseodymium chloride. So-dium(dimethylamino)borohydride. Sodium hydrogen telluride. Thexyl chloroborane-Dimethyl sulfide. Tri-n-butylphosphine-Diphenyl disulfide. Tri-n-butyltin hydride. Zinc-l,2-Dibromoethane. Zinc borohydride. [Pg.583]

The C=C double bond of 25 is reduced with sodium hydrogen telluride (NaHTe), which is a mild reagent for chemoselective reduction of a,P-unsaturated carbonyl compounds. This procedure... [Pg.246]

Use of Sodium Hydrogen Telluride. Certain a-functionalized-a,(3-unsaturated sulfones are desulfonylated using sodium hydrogen telluride in ethanol at room temperature.164-1663 u - Me thy I (hu Mi, j3-unsaturated sulfones are reduced to give vinylic thioethers in good yields albeit with moderate selectivities (Eq. 97).164 On the other hand, a-methylsulfonyl chalcones suffer tandem reduction-desulfonyla-tion in the presence of DMF as cosolvent.165,166a... [Pg.400]

Sodium hydrogen telluride. 13, 282 18.3-Reduction. Aromatic carbonyl compoi... [Pg.312]

Sodium hydrogen telluride has proven to be a versatile reductant... [Pg.240]

See other pages where Sodium hydrogen telluride reduction is mentioned: [Pg.115]    [Pg.118]    [Pg.141]    [Pg.153]    [Pg.67]    [Pg.370]    [Pg.413]    [Pg.70]    [Pg.76]    [Pg.115]    [Pg.118]    [Pg.141]    [Pg.582]    [Pg.236]    [Pg.70]    [Pg.76]    [Pg.2]    [Pg.364]    [Pg.534]    [Pg.389]   
See also in sourсe #XX -- [ Pg.880 ]

See also in sourсe #XX -- [ Pg.8 ]

See also in sourсe #XX -- [ Pg.8 ]



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