DMSO, adduct

Subsequent reaction of porphyrazines 170 and 171 with Cu(OAc)2 resulted in the selective metalation within the macrocyclic cavity to provide the corresponding copper complexes 166 (62%) and 172 (47%). Treatment of pz 170 with manganese acetate and iron sulfate in dimethyl sulfate gave the dmso adducts 173 (70%) and 174 (85%), respectively (168). Axial ligation was also observed when other metals were incorporated such as cobalt acetate, nickel acetate, and zinc acetate to give the metal complexes 175 (83%), 176 (70%), and 177 (90%) as the hydrates. The axial ligand of... 

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). 

If the oxidation of diphenylmethane in DMSO (80% )-tert-butyl alcohol (20% ) is interrupted after the absorption of one mole of oxygen per mole of diphenylmethane, one obtains an 86% yield of benzhydrol, 10% yield of unreacted diphenylmethane, and a few percent of the benzophenone-DMSO adduct. The over-all course of the reaction fol-... 

Oxidation of Benzhydrol in Basic Solution. Reaction of benzhydrol with oxygen in basic solution results in the formation of benzophenone, or in DMSO solutions the benzophenone—DMSO adduct. Table VIII summarizes data on the oxidation of benzhydrol in three solvents and in the presence of various concentrations of potassium ferf-butoxide. The rates are the maximum oxidation rates, often observed after an inductive period (Figure 3). 

The stoichiometry of the oxidation appears to require the formation of potassium superoxide as one of the oxidation products, particularly at long reaction periods and high base concentrations. An oxidation of 3.00 mmoles of benzhydrol (0.12M) in the presence of 9.9 mmoles of potassium terf-butoxide (0.37M) in DMSO (80% )-ter -butyl alcohol (20%) absorbed 4.95 mmoles of oxygen in 27.7 minutes at 25°C. and yielded 2.2 mmoles of the benzophenone-DMSO adduct and 0.8 mmole of benzophenone. A precipitate formed (0.307 gram) which analyzed (23) as 103% (4.25 mmoles) potassium superoxide (K02). 

Hydrolysis of the oxidate of anthrone resulted in the precipitation of anthraquinone (m.p. 263-268°C.). Extraction of the aqueous filtrate with chloroform yielded the DMSO adduct (1 to 1) of anthraquinone (m.p. 158-158.5°C.) (recrystallized from a chloroform-cyclohexane mixture). 

Table 37 Formation Constants for DMSO Adducts of AgCIO,271...

Since an addition reaction pathway appears to play a role in both the mechanisms of the reactions of OH and NO3 with DMSO it is surprising that the reactivity of NO3 towards DMSO is less than that towards DMS, whereas, the opposite is true for OH. This could reflect a difference in fate of the NO3-DMSO and OH-DMSO adducts. The former adduct can probably only decompose via reaction (12), whereas, the OH-DMSO adduct could react with 02 (reaction (10)) which would probably considerably shorten the lifetime of the adduct and lead to a faster overall rate constant for the reaction. This is only speculation and as mentioned in section 3.1 the possibily that secondary chemistry is effecting the OH rate determination needs to be elimated before meaningful comparisons can be made. 

The use of carbodiimides in organic synthesis includes the Moffat oxidation of primary alcohols to aldehydes using a dicyclohexylcarbodiimide/DMSO adduct as reagent. Also, conversion of alcohols or phenols into hydrocarbons via hydrogenation of acylisoureas derived from the corresponding carbodiimide adducts is a useful reaction. Furthermore, aldoximes, on treatment with carbodiimides, are converted into nitriles, and numerous uses of carbodiimides as condensation agents or catalysts are known (see Chapter 13). 

Electronic Effects. A graphic demonstration of how purely-electronic effects control the mode of coordination of the sulfoxide ligand is demonstrated in DMSO adducts of rhodium car-boxylates, [Rh2(02CR)i (DMS0)2l (11,12). The dimeric structure of the rhodium carboxylates with bridging carboxylate groups has been confirmed (3) and these readily add donor ligands L in the axial... 

Structures of the (a) Mo site of aldehyde oxidoreductase (PDB IHLR) (b) DMSO adduct to the... 

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