Ivanov salt

A completely different dipolar cycloaddition model has been proposed39 in order to rationalize the stereochemical outcome of the addition of doubly deprotonated carboxylic acids to aldehydes, which is known as the Ivanov reaction. In the irreversible reaction of phenylacetic acid with 2,2-dimethylpropanal, metal chelation is completely unfavorable. Thus simple diastereoselectivity in favor of u f/-adducts is extremely low when chelating cations, e.g., Zn2 + or Mg- +, are used. Amazingly, the most naked dianions provide the highest anti/syn ratios as indicated by the results obtained with the potassium salt in the presence of a crown ether. 

Isosteric equivalence, 77, 149 benzene and thiophene, 52 carbon and nitrogen, 399 Isothiouronium salts, as source of thiols, 44 Isothipendyl, 430 Isoxazole synthesis, 126 Isoxsuprine, 69 Ivanov reagent, 92, 93... 

The bis-deprotonation of arylacetic acids by Grignard reagents is known and the resulting bis(bromomagnesinm) salts (equation 49) have been nsed for preparing / -hydroxy acids (Ivanov reaction). 

Deposition of elemental sulphur formed from sulphate Essential collaboration of at least two different microbial species occurs in the transformation of sulphate to S° in salt domes or similar sedimentary formations (see Ivanov, 1968). This transformation is dependent on the interaction of a sulphate reducer like Desulfovibrio desulfuricans, which transforms sulphate to H2S in its anaerobic respiratory metabolism, and an H2S oxidizer like Thiobacillus thioparus, which, under conditions of limited O2 availability, transforms H2S to S° in its respiratory metabolism (van den Ende van Gemerden, 1993). The collaboration of these two physiological types of bacteria is obligatory in forming S° from sulphate because sulphate reducers cannot form S° from sulphate, even as a metabolic intermediate. It should be noted, however, that the sulphate reducers and H2S oxidizers are able to live completely independent of each other as long as the overall formation of S° from sulphate is not a requirement. 

A -methoxymethyl-amines or-amides A -acetyloxymethyl-amines or -amides or A/, iV-dimethylfonnamide acetals, all react with phosphorus(III) esters in non-classical Michaelis-Arbuzov fashion. From these and similar reactions, quaternary salts of the type 186 have been isolated. The A-methylated dervative may be preformed or produced in situ in mixtures containing amide, formaldehyde and phosphite ester. The products of the reactions are A-acylated (acetyl, benzoyl, phthaloyl, pyridinecarbonyl or benzyloxycarbonyl) when derived from amides, or A,A-dialkyl derivatives from hydroxy (or methoxy)methylamines the use of Me2NCH(OMe)2 leads to dimethylaminomethyl-enebisphosphonic esters. Ivanov and coworkers have made a detailed study of the reactions which occur between phosphorus(III) amides Et2NPYZ and the substrates, RCONHOAc (Scheme 16). The reagent can attack the substrate by virtue of the nucle-... 

The interaction between the sodium salt of phenylacetic acid and isopropyl magnesium bromide results into a doubly charged species known as the Ivanov reagent. This product on treatment with cyclopentanone affords aldol condensation to yield the corresponding hydroxy acid. The resulting product on being subjected to alkylation with N-(2-chloro-ethyl)-dimethylamine gives the desired official compound. 

Terenin VI, Ivanov AS (2007) Effect of the trifluoroacetyl group on the direction of the recyclization of the pyrazine ring in 6-trifluoroacetylpyrrolo[l,2-a]pyrazinium salts. Chem Heterocyc Comp 11 1460-1465... 

Ammonioundecafluoro-c/o5 o-dodecaborate(l-) and some A-trialkylated derivatives have been described by Ivanov et al. (2003a) as weakly coordinating anions. Equally, the dodecafluorodode-caborate has been described as weakly coordinating, despite it being a dianion (Ivanov et al., 2003b). Both salts crystallize with the triphenyhnethyl cation (PhjC+X and interaction of a cluster fluorine atom with the carbocation is found in the crystal. 

S. V. Ivanov, J. A. Davis, S. M. Miller, O. P. Anderson, S. H. Strauss, Synthesis and stability of reactive salts of dodecafluoro-closo-dodecaborate(2-). Inorg. Chem. 2003a, 42, 4489. 

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