Structure and ambiphilic reactivity of indolizines. 6. Scope of the isomerizational recyclization of indolizines

The behavior of substituted 6- and 8-nitroindolizines in the isomerizational recyclization reaction has been examined. A novel method of synthesis of 2-acyl-5- and 7-nitroindoles has been developed, by recyclization of 3-acyl-6- and 8-nitroindolizines. The scope of the isomerizational recyclization of indolizines for the synthesis of indoles has been established.For Communication 5, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 758–764, June, 1990.     

Structure and ambiphilic reactivity of indolizines. 2. 8(6)-Acetyl- and cyanoindolizines

Quaternization of 2-methyl-3(5)-acetyl and cyanopyridines with -bromoketones followed by cyclocondensation has given a number of 8(6)-acetyl- and cyanoindolizines.For Part 1, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 209–213, February, 1987.     

Synthesis of 6- and 8-nitroindolizines

A number of 6- and 8-nitroindolizines were synthesized by quaternization of isomeric 2-methylnitropyridines by -halo ketones and subsequent cyclization.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7. pp. 922–926, July, 1976.     

Structures and ambiphilic reactivities of indolizines. 5. Acylation of 2-methylindolizine

The acylation and carbomethoxylation of 2-methylindolizine were studied. In most cases minor amounts of the 1-substituted isomers were isolated in addition to the usual products of substitution in the 3 position. The data from the PMR and mass spectra of the 2-methyl-3- and 1-acylindolizines obtained are discussed.See [1] for Communication 4.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1634–1638, December, 1989.     

Enhanced nucleophilicity of ambiphilic silylene and silylenoid bearing 8-(dimethylamino)-1-naphthyl group

Some new aspects of intramolecularly amine-coordinated silylenes, ammonium silaylide, and amine-coordinated magnesium (chloro)silylenoids are summarized. The divalent silicon species bearing the 8-(dimethylamino)-1-naphthyl group, generated by the thermal degradation of a pseudo-pentacoordinated ethoxy- or fluoro-disilane, behaves as a nucleophilic ammonium silaylide as well as the amine-coordinated silylene, whose electrophilic character is weakened in comparison with that of free silylenes in some reactions in the presence of trapping agents such as 1,3-diene, diphenyl acetylene (in the absence or presence of water), and phenylacetylene, and in the absence of any trapping agent. The amine-coordinated silylenoid also behaves as an ambiphile, but the reaction courses are different from those observed with the amine-coordinated silylene and silaylide. A novel amino-group migration from naphthyl carbon to silicon has been observed in both species.     

Diazotization of the amino acid [closo-1-CB9H8-1-COOH-6-NH3] and reactivity of the [closo-1-CB9H8-1-COO-6-N2]- anion

A comparative study of the reactivity of dinitrogen acids [closo-1-CB(9)H(8)-1-COOH-10-N(2)] (3[10]) and [closo-1-CB(9)H(8)-1-COOH-6-N(2)] (3[6]) was conducted by diazotization of a mixture of amino acids [closo-1-CB(9)H(8)-1-COOH-6-NH(3)] (1[6]) and [closo-1-CB(9)H(8)-1-COOH-10-NH(3)] (1[10]) with NO(+)BF(4)(-) in the presence of a heterocyclic base (pyridine, 4-methoxypyridine, 2-picoline, or quinoline). The 10-amino acid 1[10] formed an isolable stable 10-dinitrogen acid 3[10], while the 6-dinitrogen carboxylate 3[6](-) reacted in situ, giving products of N-substitution at the B6 position with the heterocyclic solvent (4[6]). The molecular and crystal structures for pyridinium acid 4[6]a were determined by X-ray crystallography. The electronic structures and reactivity of the 6-dinitrogen derivatives of the {1-CB(9)} cluster were assessed computationally at the B3LYP/6-31G(d,p) and MP2/6-31G(d,p) levels of theory and compared to those of the 10-dinitrogen, 2-dinitrogen, and 1-dinitrogen analogues.     

Acid-catalyzed reactions of 1- and 3-(α-hydroxybenzyl)indolizines

Treatment of 1-(α-hydroxybenzyl)- and 3-(α-hydroxybenzyl)indolizines with trifluoroacetic acid in dichloromethane gave phenylbis(α-indolizinyl)methanes, bis[α-(indolizinyl)benzyl] ethers and indolizines, depending upon the presence or absence of the substituent at the 2- or 5-position and the reaction conditions used.     

Epoxidations by peracid anions in water: ambiphilic oxenoid reactivity and stereoselectivity

[reaction: see text] Transition structures have been located for oxygen transfer from performate anion to ethylene, propene, vinylamine, vinyl chloride, vinyl cyanide, and 2-propen-1-ol at the B3LYP/6-31+G(d,p) level in a CPCM continuum model for water. Oxygen transfer is concerted, except for acrylonitrile, which is stepwise. Peracid anions react as ambiphilic oxygen donors. Predictions are made about the diastereoselectivity of epoxidations of acylic, chiral, and allylic alcohols in an alkaline solution, and one is verified experimentally.     

Isomeric forms of arylnitroso oxides: Electronic spectra and reactivity

The electronic spectra were measured and the kinetics of unimolecular decomposition of the isomeric forms (cis and trans) of phenylnitroso oxide, (4-methylphenyl)nitroso oxide, (4-nitropenyl)nitroso oxide, (4-bromophenyl)nitroso oxide, 4-(N,N-dimethylamino)phenylnitroso oxide, and (4-methoxyphenyl)nitroso oxide in acetonitrile, benzene, and n-hexane was studied using flash photolysis. In all of the nitroso oxides except for 4-(N,N-dimethylamino)phenylnitroso oxide, the cis form absorbed in a shorter wavelength region and was more labile than the trans form. The difference between the reactivity of the two species increased on going from n-hexane to acetonitrile. The temperature dependence of reaction rate constants was studied for both of the isomeric forms. Unlike the trans isomer, the cis isomer almost did not react with tetramethylethylene.     

Isomeric methoxy derivatives of 6-nitro-9-(p-anisylamino)acridine

1-, 2-, 3-, and 4-methoxy derivatives of 6-nitro-9-(p-anisylamino) acridine ate synthesized.     

Indolizines. 6. Relative reactivities of isomeric 6-, 7-, and 8-ethoxycarbonylindolizine derivatives

The kinetics of the alkaline hydrolysis of 2-phenyl-6-, -7-, and -8-ethoxycarbonylindolizines were studied. The rate constants for the hydrolysis of these compounds and the indexes of the dissociation constants of 2-phenylindolizine-6-,-7-, and -8-carboxylic acids were determined by spectrophotometry. The indexes of the electronic structures and reactivities of 2-methyl-6-, -7-, and -8-ethoxycarbonylindolizines were calculated from theory.See [1] for Communication [5].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 627–633, May, 1979.     

Synthesis of 2-(furazanyl)indolizines

Heating ofN-[2-(4-methylfurazan-3-yl)-2-oxoethyl]-2-methylpyridinium bromides inN,N-dimethylaniline affords indolizine derivatives, whereas in aniline a mixture of indole and indolizine derivatives is formed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp.2375–2376, December, 1999.