Potassium ferf-butylate

Pradilla et al. have shown that simple p-tolyl vinyl sulfoxides undergo nucleophilic epoxidation with metal alkyl peroxides to give enantiopure sulfinyl oxiranes.138 This process takes place with fair to excellent diastereoselectivities. The same group recently reported the epoxidation of diastereomeric hydroxy vinyl sulfoxides, bearing an additional stereocenter adjacent to the reactive carbon-carbon double bond. Hydroxy vinyl sulfoxides 256 and 258 underwent epoxidation with lithium ferf-butyl peroxide with high anti selectivity. However, when potassium ferf-butyl peroxide was used, only hydroxy vinyl sulfoxide 256 showed anti... 

Similarly, sodium methoxide (NaOCHj) is a suitable base and is used in methyl alcohol. Potassium hydroxide in ethyl alcohol is another base-solvent combination often employed in the dehydrohalogenation of alkyl halides. Potassium ferf-butoxide [K0C(CH3)3] is the prefened base when the alkyl halide is primary it is used in either terf-butyl alcohol or dimethyl sulfoxide as solvent. 

A series of pyrazoles [pyrazole, 3,5-dimefliyl-, 3(5)-ferf-butyl, 3-methyt-5-ferf-butyl-, 3(5)-phenyl-,3-methyl-5-phenyl-, 3(5)-p-meflioxyphenylpyrazole] reacts wifli [Rh(/r-Cl)( 7 -nbd)]2 in die presence of potassium hydroxide to give [Rh(/r-Pz)(jj -nbd)]2 [96JOM(511)l 15]. For the 3(5)-tm-butylpyrazolato dimer. 

Besides the technical method starting from naphthalene, phthalic acid and its substituted derivatives can be prepared by oxidation of o-xylene to phthalic acid with potassium permanganate. This compound can be subsequently transformed via an anhydride, imide, and amide to a derivative of phthalonitrile, which is the more convenient starting material for several coordination compounds. The synthesis of the ferf-butyl-substituted dicarbonitrile, which is a very common starting material for highly soluble phthalocyanines, is shown below.97,105... 

Feuer and co-workers also nitrated ring-substituted toluenes to the corresponding arylnitromethanes with potassium amide in liquid ammonia. Sulfonate esters and NJ -dialkylamides undergo similar nitration the latter isolated as their a-bromo derivatives. Alkaline nitration of ethyl and ferf-butyl carboxylic esters with potassium amide in liquid ammonia yields both the a-nitroester and the corresponding nitroalkane from decarboxylation. ... 

Marchand and co-workers reported a synthetic route to TNAZ (18) involving a novel electrophilic addition of NO+ NO2 across the highly strained C(3)-N bond of 3-(bromomethyl)-l-azabicyclo[1.1.0]butane (21), the latter prepared as a nonisolatable intermediate from the reaction of the bromide salt of tris(bromomethyl)methylamine (20) with aqueous sodium hydroxide under reduced pressure. The product of this reaction, A-nitroso-3-bromomethyl-3-nitroazetidine (22), is formed in 10% yield but is also accompanied by A-nitroso-3-bromomethyl-3-hydroxyazetidine as a by-product. Isolation of (22) from this mixture, followed by treatment with a solution of nitric acid in trifluoroacetic anhydride, leads to nitrolysis of the ferf-butyl group and yields (23). Treatment of (23) with sodium bicarbonate and sodium iodide in DMSO leads to hydrolysis of the bromomethyl group and the formation of (24). The synthesis of TNAZ (18) is completed by deformylation of (24), followed by oxidative nitration, both processes achieved in one pot with an alkaline solution of sodium nitrite, potassium ferricyanide and sodium persulfate. This route to TNAZ gives a low overall yield and is not suitable for large scale manufacture. 

Carbazole can be efficiently tetra-ferf-butylated with tcrt-butylchloride and aluminium chloride at room temperature giving 141 K. 4i,85. traces of 3,6-di- and 1,3,6-tri-tert-butylcarbazoles are also produced. 3-Formyl-2-hydroxycarbazole is alkylated at C-1 with dimethylallyl chloride in the presence of 30% aqueous potassium hydroxide. ... 

Oxidation of Diphenylmethane in Basic Solution. Diphenylmethane reacts with an excess of oxygen in the presence of potassium ferf-butoxide in various solvents to produce nearly quantitative yields of benzophenone. In DMSO (80% )-tert-butyl alcohol (20% ) a 96% yield of the benzo-phenone-DMSO adduct [ l,l-diphenyl-2- (methylsulfinyl) ethanol] was isolated at complete reaction (17). 

This interpretation was proved correct by considering the oxidation of a sample of diphenylmethane that had an isotopic purity of 97.0% a,a-dideuterio and 2.7% a-deuterio by mass spectrometry. The oxidation rate observed after the initial 15-second period (see Figure 2), during which the undeuterated and monodeuterated material were destroyed, yielded a second-order rate constant, ki = 0.0148 mole"1 per second. There is thus an appreciable isotope effect ku/kD of about 6 in the ionization of diphenylmethane by potassium ferf-butoxide in DMSO(80%)-tert-butyl alcohol (20% ) at 25°C. This compares with a value of fcH/ D of 9.5 reported for the ionization of triphenylmethane (16). The observation of primary isotope effects of this magnitude requires that the protonation of the diphenylmethide ion by tert-butyl alcohol in DMSO solution does not proceed at the diffusion rate which would, by the principle of microscopic reversibility, require the absence of an isotope effect in the deprotonation step. 

Ferric chloride (0.002M) reduced the rate of oxidation of benzhydrol (0.15M) in the presence of 0.39M potassium ferf-butoxide in tert-butyl alcohol to a rate of 0.001 mole of oxygen per mole of benzhydrol per minute, while arsenic trioxide (0.01M) reduced the rate of oxidation of 0.12M benzhydrol and 0.36M potassium ferf-butoxide to 0.0001 mole of oxygen per mole of benzhydrol per minute for a 4-hour period, after which the oxidation occurred at the uninhibited rate (Figure 3). Table IX summarizes some observed stoichiometries in the oxidation of benzhydrol. 

M xanthenol, 0.22M potassium ferf-butoxide in pyridine (80% )—terf-butyl alcohol (20% ) solution at 27° 3°C. b Moles of oxygen/mole of substrate per minute. 

Interrupted oxidations of 9,10-dihydroanthracene or 9,10-dihydro-phenanthrene in DMSO (80% )-terf-butyl alcohol (20%) containing potassium ferf-butoxide produced the 9,10-semiquinone radical anions, apparently as a product of oxidation of the monoanion. 

In order to keep down the volume of the reaction mixture, less ferf-butyl alcohol is used than is necessary to dissolve the potassium JerZ-butoxide. 

II ferf-Butoxy-l-chloromethylsulfonyl)-4 methylbenzene, 57, 100 sec-Butyl alcohol, 58, 78 ferf-Butyl alcohol, 58, 78 ferf-Butyl alcohol, potassium salt, 56, 29 rerf-Butylamine, 55, 96 1 Butvl-2-chlorobenzene 58, 133... 

Some of the polymers slowly change their helicity in solution. A chiral crown ether-potassium ferf-butoxide combined system was reported to cause polymerization of methyl, tert-butyl, and benzyl methacrylate to form isotactic polymers that had high rotation values (164). Detailed scrutiny, however, raised questions about the result (135, 165). At first, in the presence of the initiator, the oligomers exhibit considerable activity, but after removal of the catalyst, the optical activity decreases. This decrease may be attributed to unwinding of the helixes in the chain the helicity could be caused by the anchored catalyst. 

Potassium ferf-butoxide reacts with halobenzenes on heating in dimethyl sulfoxide to give ferf-butyl phenyl ether. 

Exercise 17-43 Write a mechanism analogous to that for the Cannizzaro reaction for the benzilic acid transformation. What product would you expect to be formed from diphenylethanedione with potassium terf-butoxide in ferf-butyl alcohol Would you expect a benzilic acid-type rearrangement to occur with 2,3-butanedione Give your reasoning. 

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