N-aminorhodamne complexes of palladium(II), palladium(IV) and platinum(II)

Summary TheN-aminorhodanine (L) complexes: PdLX, (X = Br or I), ML_1.5Cl₂ (M = Pd or Pt), PtL₂X₂ (X = Br, I or ClO₄), PdL₃(ClO₄)₂, PdL_1.5Cl₄ and PdL₃(ClO₄)₄ have been prepared and investigated. The ligand is bonded to the metal ion through the aminic nitrogen atom as monodentate or through this atom and the thiocarbonylic sulphur atom when it acts as chelating or bridging ligand. The carbonylic oxygen atom is never coordinated.     

Advances in the Synthesis of New Organic Reagents for the Determination of Noble and Heavy Metals

Results are summarized on the synthesis of reagents for the determination of noble and heavy metals (sulfonitrophenol M, sulfochlorophenolazorhodanine (Rhodazol KhS), chlorophenolazorhodanine (Rhodazol Kh), sulfobenzeneazorhodanines, p-phenolazo-3-aminorhodanine, benzeneazobenzeneazorhodanine, sulfochlorophenolazothiopropiorhodanine (tyrodine), and hexaoxacycloazochrom), methods for their purification and identification, the determination of the concentration of the active compound in reagents, and techniques for the storage of reagents and the preparation of working solutions.     

Synthesis of new arylidene derivatives of 3-aminorhodanine

The synthesis of new arylidene derivatives of 3 -aminorhodanine has been effected. It has been established that the condensation of 3-aminorhodanine with aldehydes in an alcoholic medium gives 3-arylidene derivatives. Similar reactions in an ammoniacal medium lead to 5-derivatives of 3-aminorhodanine. 3, 5-Diarylidene derivatives can be obtained by condensing 3-aminorhodanine with an excess of an aldehyde in glacial acetic acid, except for the salicylidene and 9-anthrylidene derivatives, the synthesis of which can be carried out only in two stages.     

Intermittent compression of N-alkyl-N,N-dimethylamine N-oxides encapsulated in a container with bis[2]catenane topology

Abstract

We report the encapsulation of a homologous series of N-alkyl-N,N-dimethylamine N-oxides in a molecular container with bis[2]catenane topology. N-oxides with short alkyl chains are co-encapsulated with one solvent molecule. Elongation of the alkyl chain from R = methyl to pentyl produced the progressive compression of the guest. The hexyl N-oxide reduces its compression by being singly encapsulated. Longer N-oxides (R = octyl to decyl) had to fold to adapt to the capsule’s dimensions and also experience a progressive compression. The mechanically interlocked nature of the container and the polar functionalisation of its cavity are responsible for the assembly of encapsulation complexes in solution displaying high packing coefficients (0.65–0.70). The high energy conformations adopted by the alkyl chains of the bound N-oxides are deduced from NMR experiments and molecular modelling studies.     

A New Route to N‐Aryl 2‐Alkenamides,N‐Allyl N‐Aryl 2‐Alkenamides,and N‐Aryl α,β‐Unsaturated γ‐Lactams from N‐Aryl 3‐(Phenylsulfonyl)propanamides

A series of N‐aryl 2‐alkenamides were produced efficiently by treating N‐aryl 3‐(phenylsulfonyl)‐propanamides with potassium tert‐butoxide in THF at 0°C. With out isolation, it was further treated with an additional equivalent of potassium tert‐butoxide and allyl bromide to give N‐allyl N‐aryl 2‐alkenamides in one pot in good yields. Followed by a ring‐closing metathesis reaction, these N‐allyl N‐aryl 2‐alkenamides were respectively converted into corresponding N‐aryl α,β‐unsaturated γ‐lactams in moderate yields.     

Synthesis of new chiral mono-, di-, tri-, and tetraalkylglycolurils

Two general procedures were developed for the synthesis of chiral N-mono-, N, N′-di-, N, N′ N″-tri-, and N, N′, N″, N′″-tetraalkylglycolurils based on the reactions of 4,5-dihydroxy-imidazolidin-2-ones or glyoxal with one or two moles of alkylureas, respectively, by acid catalysis. The reactions of N-monoalkyl- and N, N′-dialkylureas with glyoxal proceed regioselectively. The mechanism of these reactions was suggested and partly confirmed by quantum-chemical calculations and experimental data. The enantiomeric separation of some chiral glycolurils by chiral-phase HPLC was carried out for the first time.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 680–692, March, 2005.     

Polymerization of N,N-Dialkylacrylamides with Anionic Initiators Modified by Diethylzinc

Abstract

N,N-Dimethyl-, diethyl-, and dipropylacrylamides were polymerized with 1,1-bis(4′-trimethylsilylphenyl)-3-methylpentyllithium (I) in the presence and absence of diethylzinc in THF. Although the polymers produced with I in the absence of diethylzinc have rather broad molecular weight distributions, the addition of diethylzinc to the polymerization systems causes narrow molecular weight distributions of the polymers. The addition of diethylzinc also affect the stereospecificities of the polymers obtained. The poly(N,N-diethylacrylamide) produced with I/diethylzinc (molar ratio of 1/3-15) is highly syndiotactic, while the one obtained with I is isotactic. The configuration of the poly(N,N-dimethylacrylamide) is changed from isotactic to syndio and heterotactic rich by the addition of diethylzinc to the polymerization mixture. Little effect of diethylzinc is observed on the stereospecificity of the polymerization of N,N-dipropylacrylamide. The stoichiometric additive effect of Et₂Zn toward the initiator in the polymerization of DEAA suggests that the coordination of Et₂Zn aggregates with the propagating carbanionic species narrows the molecular weight distribution and controls the tacticity of the polymer.     

KF/Al2O3 as an Efficient,Green, and Reusable Catalytic System for the Solvent-Free Synthesis of N-Alkyl Derivatives of Sulfonamides via Michael Reactions

KF/Al ₂ O ₃ efficiently catalyzes the microwave-assisted Michael addition of sulfonamides to α,β-unsaturated esters under solvent-free conditions to afford N-alkyl derivatives of sulfonamides as biologically interesting compounds in high yields and in short reaction times. In this reaction, N,N-dialkylsulfonamides are also produced, but in very low yields.     

Aminopropylcellulose,synthesis and derivatization

The preparation of 3-aminopropylcellulose from cyanoethylcellulose is readily achieved. Reduction of the cyano groups with borane-dimethyl sulfide in tetrahydrofuran or a borane-tetrahy-drofuran complex proceeds quantitatively in 3 h to a corresponding 3-aminopropylcellulose. The presence of primary amine functions is confirmed by spectroscopy and a positive ninhydrin test; the concentration of amino substituents, as ascertained by titration, ranged from 1.2 to 6.4 meq/g. Because the derivatives are neither soluble nor excessively swollen in water, applications as ion-exchange resins or chromatographic supports can be envisioned. Treatment of 3-aminopropyl-cellulose with acetyl chloride, phenyl isocyanate, or p-toluenesulfonyl isocyanate produced 3-acetamido-, 3-(N′-phenyluredo)-, or 3-(N′-p-toluenesulfonyluredo)-N-propylcellulose. Alkylation with methyl chloride yielded a water-soluble quaternary ammonium salt.     

The photochemical reactions of the halogenated N-benzylanilines. Mechanism of the reactions

Several N-(2-halobenzyl)anilines and N-benzyl-2-haloanilines have been synthesized and their photochemical reactions studied. Upon irradiation, the aqueous acetonitrile solution of N-benzyl-2-chloroaniline was cyclized and reduced to give phenanthridine, 5,5′,6,6′-tetrahydro-6,6′-biphenanthridyl (THBP), N-ben-zylaniline, and bibenzyl. Similar products were produced in the photochemical reactions of other halo-genated N-benzylanilines, except iodo-substituted N-benzylanilines. No dimer (THBP) was produced from the iodo-substituted N-benzylanilines. Both singlet and triplet states are involved in the photochemical reactions of the haloarenes.     

Theoretical Study of Molecular Structure,Reactivity, Lipophilicity,and Solubility of N-Hydroxyurea,N-Hydroxythiourea,and N-Hydroxysilaurea

Ab initio molecular orbital methods at the CBS-QB3 level of theory have been used to study the structure and gas-phase stability of various tautomers and rotamers of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and protonated forms. The geometries of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and cations were optimized at the Becke3LYP/CBSB7 level of theory. For all compounds studied, the amidic form is computed to be substantially more stable than the iminolic tautomer. N-Hydroxyurea and its thio and sila derivatives are computed to behave as Nacids in the gas phase. These compounds are in gas-phase weak acids with a calculated acidity of about 1425 to 1355 kJ-mol^–1. Basicities increase in the order: N-hydroxyurea < N-hydroxythiourea < N-hydroxysilaurea. The most stable protonated structures are represented by several isomers with almost equal stability. Thus, in the N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, both protonation at the double bonded (C=O, C=S and Si=O) oxygen and sulfur atoms, as well as the protonation at the N(H)OH nitrogen basic center is equally probable. The experimental pK _a value (10.6) of N-hydroxyurea and the computed value (9.7) for its monohydrated complex with the specifically hydrogen-bonded water molecule to the ionizable OH group are in a good agreement. The experimental partition coefficient of N-hydroxyurea is best reproduced by the Alog P_s method. The formation of nitroxide radical in the reaction of N-hydroxyurea and its sulfur and silicon substituted derivatives with the phenol radical is an exothermic process. Thus, the \bondN(H)OH moiety of these compounds may quench the structurally related tyrosyl radicals in the active site of ribonucleotide reductase.     

The synthesis and solution properties of some rigid-chain,water-soluble polymers: Poly[N,N′-(sulfo-phenylene)phthalamide]s and poly[N,N′-(sulfo-p-phenylene)pyromellitimide]

Poly[N,N′-(sulfo-phenylene)phthalamid]es and poly[N,N′-(sulfo-p-phenylene)pyromellitimide] were prepared in water-soluble form and were found to have unique solution properties, similar in some respects to xanthan. The polymer most investigated, poly[N,N′-(sulfo-p-phenylene)terephthalamide] (PPT-S), is produced as the dimethylacetamide (DMAC) salt by the solution polymerization of 2,5-diaminobenzenesulfonic acid with terephthaloyl chloride in DMAC containing LiCl. The isolated polymer requires heating in water to dissolve; the resulting cooled solutions are viscous or gels at concentrations as low as 0.4%. They are highly birefringent, exhibit circular dichroism properties, and are viscosity-sensitive to salt. Solutions of this polymer mixed with those of guar or hydroxyethyl cellulose give significantly enhanced viscosity. The polymer is relatively low molecular weight, ca. 5000 estimated from viscosity data. Some meta and para isomeric analogs of PPT-S were prepared; these polymers have similar properties except they are more soluble in water, and higher concentrations are required to obtain significant viscosity. Poly[N,N′-(sulfo-p-phenylene) pyromellitimide] (PIM-S) was prepared similarly from 2,5-diaminobenzenesulfonic acid and pyromellitic dianhydride. Its aqueous solution properties are similar to those of PPT-S. It appears that these relatively low-molecular-weight rigid-chain polymers associate in water to form a network that results in viscous solutions at low concentrations.     

Palladium-Catalyzed Ring-Opening Addition of Activated Vinyl Cyclopropanes with N-Tosylhydrazones

Ring-opening addition reaction of activated vinyl cyclopropanes with N-tosylhydrazones in the presence of palladium(0) and triphenylphosphine affords N-tosylhydrazone butenylmalonate compounds. Aromatic aldehyde-derived N-tosylhydrazones produced terminal and internal N-allylated products, in which the terminal products are the main. While ketone-derived tosylhydrazones produced only terminal addition products. The transformation relationship of the terminal and internal N-allylated products in the reaction was also observed. A reasonable mechanism is proposed based on preliminary experimental results.     

Geminal systems. 50. Synthesis and alcoholysis of N-acyloxy-N-alkoxy derivatives of ureas,carbamates, and benzamides

Procedures were developed for the synthesis of N-acyloxy-N-alkoxy derivatives of ureas, carbamates, and benzamides by the reactions of the corresponding N-alkoxy-N-chloro derivatives with sodium carboxylates in MeCN. N-Chloro-N-ethoxy-p-toluenesulfonamide was inert in this reaction. Alcoholysis of N-acyloxy-N-alkoxy derivatives of ureas, carbamates, and tert-alkylamines afforded the corresponding N,N-dialkoxy derivatives, whereas alcoholysis of N-acetoxy-N-ethoxybenzamide gave rise to alkyl benzoates.     

Synthesis and attempted polymerization of N-arylmaleimides substituted with allylamino or cyclopropylamino groups at 2-position

Several N-substituted chloromaleimides were prepared by dehydrating the corresponding chloromaleamic acids. Treatment of chloromaleimides with allylamine or cyclopropylamine produced N-aryl-2-(allylamino)maleimides and N-aryl-2-(cyclopropylamino)maleimides, respectively. Neither the N-substituted chloromaleimides nor the N-aryl-2-(allylamino) or N-aryl-2-(cyclopropylamino)maleimides polymerized free radically or anionically. The difficulty of achieving good pi-pi overlap and stiric effects at the propagation step prevented the cyclopolymerization of the prepared 1,5-dienes.     

Preparation of certain 2-N-alkylamino-and 2-N,N-dialkylamino-10-methylphenothiazines via phenothiazyne

The treatment of 2-chloro-10-methylphenothiazine, 1 , with lithium alkylamide/alkylamine or lithium dialkylamide/dialkylamine yields the corresponding 2-N-alkylamino-or 2-N,N-dialkylaminophenothiazines in good yields via phenothiazyne. No significant reduction of 1 to 10-methylphenothiazine is observed. Yields of amines obtained by this method are considerably higher than those obtained by reacting 1 with sodamide in refluxing amine solvent. Attempts to introduce the -CH₂CN moiety onto the phenothiazine nucleus by treating 1 with sodamide and acetonitrile in liquid ammonia produced only 2-amino-10-methylphenothiazine.     

The Electrochemically Initiated Reaction of Sulfide with N,N‐Diethyl‐p‐phenylenediamine in Dimethylformamide. Part II: Implications for Sensing Strategies

The electrochemically initiated reaction of p‐phenylenediamines with sulfide in aqueous media is well documented. We now report the adaptation of this chemistry into nonaqueous media. This is critically appraised as a means of detecting sulfide. The electrochemically initiated reaction of N,N‐diethyl‐p‐phenylenediamine with sulfide is shown at both macro‐ and platinum microdisk electrodes with quantitative detection of sulfide produced by means of the enhanced currents observed upon its addition. The linear detection range for sulfide is dependent on the concentration of N,N‐diethyl‐p‐phenylenediamine present with a linear range from 28–3290 μM and a limit of detection of 22 μM achievable. This represents a large increase compared to that found previously in aqueous media and offers the prospect of more ready applications in high temperature systems.     

N‐chloro amides,lactams, carbamates,and imides. New classes of initiators for the metal‐catalyzed living radical polymerization of methacrylates

Metal‐catalyzed living radical polymerization of methyl methacrylate initiated with N‐chloro amides (N‐chloro N‐ethyl propionamide, N‐chloro benzanilide, N‐chloro methylbenzamide, and N‐chloro acetanilide), lactams (N‐chloro caprolactam and N‐chloro 2‐pyrrolidinone), carbamates or urethanes (N‐chloro ethylcarbamate or N‐chlorourethane), imides (N‐chloro phtalimide, N‐chloro succinimide, trichloroisocyanuric acid, and N‐chloro saccharin) and catalyzed with the self‐regulated catalytic system Cu₂S/2,2′‐bipyridine is reported. The initiation efficiency of these initiators is determined by their structure. Regardless of the initiator efficiency, in all cases, poly (methyl methacrylate) with narrow molecular weight distribution and functionalized chain‐ends was obtained. These new classes of initiators open new strategies for the functionalization of polymer chain‐ends and for the synthesis of complex architectures by graft copolymerization initiated from N‐chloro proteins, aliphatic, aromatic and semiaromatic polyamides, and polyurethanes. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5283–5299, 2005     

Photo-elimination of nitrogen from fused-ring triazoles

By irradiation in methanol at 3000Å, aniline and o-anisidine were produced from benzo-triazole and N-methylaniline and N-methyl-o-anisidine were produced from N-methylbenzotriazole. Carbazole was the only product detected from similar treatment of N-phenylbenzotriazole. Linear naphthotriazole was photolytically transformed into β-naphthylamine but a methoxy derivative could not be found. Angular naphthotriazole gave no identifiable photolytic product. u-Triazolo[1,5-α]pyridine underwent photolysis in methanol to give α-picoline, α-picolylmethyl ether and α-picolylmethanol in low yield. A similar photolysis in acetic acid afforded α-pyridylmethyl acetate. The mechanisms for the formations of products are discussed.     

Synthesis of new arylidene derivatives of 3-aminorhodanine

The synthesis of new arylidene derivatives of 3 -aminorhodanine has been effected. It has been established that the condensation of 3-aminorhodanine with aldehydes in an alcoholic medium gives 3′-arylidene derivatives. Similar reactions in an ammoniacal medium lead to 5-derivatives of 3-aminorhodanine. 3′, 5-Diarylidene derivatives can be obtained by condensing 3′-aminorhodanine with an excess of an aldehyde in glacial acetic acid, except for the salicylidene and 9-anthrylidene derivatives, the synthesis of which can be carried out only in two stages.