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V. A. Ioffe

Bio: V. A. Ioffe is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Sodium & Cyanide. The author has an hindex of 2, co-authored 8 publications receiving 6 citations.

Papers
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Journal ArticleDOI
TL;DR: The azacycloalkanes HNCH2(CH2)nCH2CH2 (n=1−3), on treatment with the Na2S2O8-NaCN-NaOH system, undergo the competing reactions of N-cyanation to give the ureas, C-Cyanation and β-fragmentation to give 2-cyanoazacycloencane, and N
Abstract: 1. The azacycloalkanes HNCH2(CH2)nCH2CH2 (n=1–3), on treatment with the Na2S2O8-NaCN-NaOH system, undergo the competing reactions of N-cyanation to give the ureas, C-cyanation to give 2-cyanoazacycloalkanes, and β-fragmentation to give N-cyanomethyl- and N-formylazacycloalkanes. The relative proportions of these three competing reactions depend on the size of the ring. 2. Oxidative β-fragmentation of azacycloalkanes also occurs in the K3Fe(CN)6-NaOH and Na2S2O8-AgNO3-NaOH systems.

4 citations

Journal ArticleDOI
TL;DR: In the Na2S2O8-NaCN-NaOH system, oxidation of dialkylamines by a mechanism of oxidative substitution with the formation of the products of N-cyanidation: cyanamides and ureas, and the products from N-hydroxylation, dialkylhydroxylamines, predominate.
Abstract: 1. In the Na2S2O8-CuCl2 system, secondary aliphatic amines (RCH2CH2)2NH are transformed into 2-chloro- and 2,2-dichloroalkanals, alkanoic acids and their alkylamides; their most probable precursors are RCH2CH=NCH2CH2R azomethines, formed as a result of oxidative deprotonation. 2. In the Na2S2O8-NaCN-NaOH system, oxidation of dialkylamines by a mechanism of oxidative substitution with the formation of the products of N-cyanidation: cyanamides and ureas, and the products of N-hydroxylation, dialkylhydroxylamines, predominate.

2 citations

Journal ArticleDOI
TL;DR: In this paper, a simple method for separating reaction products has been developed to distinguish reaction products in a sodium peroxydisulfate-sodium cyanide system, and the introduction of sodium hydroxide to the oxidizing system favors the increase in the yield of alkylureas and 2-(Alkylamino)alkanonitriles.
Abstract: 1. In a sodium peroxydisulfate-sodium cyanide system, the aminyl radicals RCH2CH2NH generated from n-alky1amines undergo N-cyanation to form alkylureas, and are oxidized to aldimines, predecessors of N-alkyl alkanamides and 2,5,6-trialkyl-1,3-diox-4-enes. 2. The introduction of sodium hydroxide to the oxidizing system favors the increase in the yield of alkylureas and alkyl cyanamides to 70%. 2-(Alkylamino)alkanonitriles are also formed. A simple method for separating the reaction products has been developed. 3. In the oxidation of sec-alkylamine, cyclohexylamine, oxidative deprotonation predominates over the N-cyanation reaction.

1 citations

Journal ArticleDOI
TL;DR: In this article, the Na2S2O8-CuCl2 system converted primary aliphatic amines into nitriles RCH2CN, 2,2-dichloroalkanals RCCl2CHO, acids RCH 2COOH, and chloroalkanes R CH2CH2Cl.
Abstract: 1. Primary aliphatic amines RCH2CH2NH2 are converted by the action of the Na2S2O8-CuCl2 system into nitriles RCH2CN, 2,2-dichloroalkanals RCCl2CHO, acids RCH2COOH, and chloroalkanes RCH2CH2Cl. The formation of 2, 2-dichloroalkanals and chloroalkanes are new reactions of oxidative substitution of the amino group in primary aliphatic amines. 2. A mechanism for the reactions has been proposed, including the production of aminyl radicals RCH2-CH2NH and their oxidation into aldimines RCH2CH=NH, predecessors of all the reaction products.

Cited by
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Journal ArticleDOI
TL;DR: Mechanistic studies suggest that the carboxylic acid additive has three effects: formation of a stabilizing hemiaminal intermediate, prevention of catalyst decomposition by protonating the substrate, and modulation of fluorescence quenching of the photoexcited catalyst species.
Abstract: This paper describes the development and mechanistic studies of a general, high-yielding amine Cα–H cyanation protocol via photoredox catalysis. Inexpensive NaCN is employed as the cyanide source and air is the external oxidant, resulting in mild and highly functional group tolerant conditions. Notably, efficient Cα–H cyanations of secondary and tertiary aliphatic amines and of complex, biologically active compounds (drugs) can be performed using the established methodology. Mechanistic studies suggest that the carboxylic acid additive has three effects: formation of a stabilizing hemiaminal intermediate, prevention of catalyst decomposition by protonating the substrate, and modulation of fluorescence quenching of the photoexcited catalyst species.

33 citations

Journal ArticleDOI
TL;DR: This oxidative N-cyanation reaction allows for the preparation of disubstituted cyanamides from amines without using highly toxic cyanogen halides.

23 citations

Dissertation
31 Jan 2007
TL;DR: It is demonstrated that as tris(triethanolammonium) salts, these amphiphiles show excellent solubility in water.
Abstract: Many previous studies of biological activity in a homologous series of amphiphiles have shown a cut-off effect, where the biological activity increases with an increase in chain length, after which the activity plateaus or weakens. One factor suspected to cause this problem is solubility issues. We have designed several series of very hydrophobic, water-soluble amphiphiles to overcome this problem. Three homologous series containing mobile hydrophobic moieties and two series of epimers containing rigid cholestane moieties have been synthesized; the hydrophobic moiety is connected to the first-generation, Newkome-type dendron via a ureido linker. We have demonstrated that as tris(triethanolammonium) salts, these amphiphiles show excellent solubility in water. The solubilities in aqueous solution of the three series containing mobile hydrophobic moieties are 19,500 to 25,700 μM depending on the formula weight of the homolog, while those containing rigid cholestane moieties are 18,900 and 17,400

8 citations

Book ChapterDOI
TL;DR: The chemistry of N,N′-bisazaheterocycles is gaining importance recently because of their potential role in widening the available pool of chiral auxiliaries in asymmetric synthesis; discovering new molecules as drug candidates; and unraveling the molecular mechanics and bioactivity of cyclic aminyl radicals as mentioned in this paper.
Abstract: The chemistry of N,N′-bisazaheterocycles is gaining importance recently because of their potential role in (1) widening the available pool of chiral auxiliaries in asymmetric synthesis; (2) discovering new molecules as drug candidates; (3) developing organic polymers for use in light harvesting devices; and (4) unraveling the molecular mechanics and bioactivity of cyclic aminyl radicals. The synthetic approaches to these compounds, reported in literature till August 2014, are summarized in this chapter. For this purpose, N,N′-bisazaheterocycles have been classified as “symmetrical” (A–A type) and “unsymmetrical” (A–B type), based on whether the heterocyclic rings present on either side of the N–N bond in the molecule are same or different. Accordingly, the synthesis and importance of N,N′-biaziridines (with ring sizes being 3–3), biazetidine (4–4), biazoles (5–5), biazines (6–6), biazepanes (7–7), and aziridinyl azoles (3–5), aziridinyl azines (3–6), azetidinyl azoles (4–6), azetidinyl azines (4–6), azolyl azoles (5–5′), azolyl azines (5–6), azolyl azepines (5–7), azolyl azocanes (5–8), azinyl azines (6–6′), azinyl azepines (6–7) are discussed.

7 citations