Addition Of Tertiary Amines Research Articles

3+2]-Cycloaddition of Nitrile Imines to Parabanic Acid Derivatives-An Approach to Novel Spiroimidazolidinediones.

Approximately 1,3-Dipolar cycloaddition of imidazolidine derivatives containing exocyclic double bonds is a convenient method of creating spiro-conjugated molecules with promising anticancer activity. In this work, the derivatives of parabanic acid (2-thioxoimidazolidine-4,5-diones and 5-aryliminoimidazolidine-2,4-diones) were first investigated as dipolarophiles in the reactions with nitrile imines. The generation of nitrile imines was carried out either by the addition of tertiary amine to hydrazonoyl chlorides «drop by drop» or using the recently proposed diffusion mixing technique, which led to ~5-15% increases in target compound yields. It was found that the addition of nitrile imines to C=S or C=N exocyclic double bonds led to 1,2,4-thiazolines or triazolines and occurred regioselectively in accordance with the ratio of FMO coefficients of reactants. The yield of the resulting spiro-compound depended on the presence of alkyl substituents in the nitrile imine structure and was significantly decreased in reactions with imines with strong electron donor or electron-withdrawing groups. Some of the obtained compounds showed reasonable in vitro cytotoxicity. IC50 values were calculated for HCT116 (colon cancer) cells using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test.

Chemical Modification of Poly(1-Trimethylsylil-1-Propyne) for the Creation of Highly Efficient CO2-Selective Membrane Materials.

The work is devoted to the chemical modification of a polymer that is promising for the creation of gas separation membranes, aimed at increasing the selectivity with respect to CO2. The introduction of ionic liquids into the structure of poly(1-trimethylsilyl-1-propyne) is realized by a two-step process: bromination of the initial polymer with N-bromosuccinimide and subsequent addition of tertiary amine (N-butylimidazole) to it. Depending on the process conditions, the method allows polymers with different contents of the ionic liquid to be obtained. The obtained polymers show good film-forming properties and thermal stability. Depending on the content of the ionic liquid in the polymer matrix, the resistance to aliphatic alicyclic to the majority of halogenated, as well as aromatic hydrocarbons, increases. With an increase of the ionic liquid content in the polymer, the ideal selectivities of CO2/N2 and CO2/CH4 gas pairs increases while maintaining a high level of permeability.

An energetic derivative of 2,2′,4,4′,6,6′-hexanitrostilbene (HNS) and its DMF solvate crystallized from HNS solution with tertiary amine additives

ABSTRACTAn energetic derivative of 2,2′,4,4′,6,6′-hexanitrostilbene (HNS) and 2,4,7,9-tetranitro-10H-benzofuro[3,2-b]indole (TNBFI) has been synthesized from the N,N-dimethylformamide (DMF) solution of HNS with different tertiary amine additives, 4-(4-pyridyl)morpholine and 1,1-bis(morpholino) ethylene. TNBFI crystallized with DMF in a solvate, TNBFI·2DMF, was identified by negative ESI mass spectrum and single-crystal X-ray diffractions. The 3D-supermolecular structure of TNBFI·2DMF was built from the alternate stacking of TNBFI and DMF layers with π-stacking interactions between TNBFI molecules and H-bonding interactions between TNBFI and DMF molecules. The energetic properties of TNBFI molecule as well as the thermal stability of its DMF solvate have been investigated.

Efficient oxidative N -dealkylative addition of trialkylamines to dimethyl acetylenedicarboxylate using BrCCl 3 as the terminal oxidant

Abstract Herein we present a continuous improvement of visible-light mediated N -dealkylative addition of tertiary amines to dimethyl acetylenedicarboxylates (DMAD) using alkyl halogenides as external oxidants together with base additives. This method is highlighted by excellent tolerance with various tertiary amines and good to excellent yields in short reaction time under mild conditions.

Towards the design of organocatalysts for nerve agents remediation: The case of the active hydrolysis of DCNP (a Tabun mimic) catalyzed by simple amine-containing derivatives

We report herein a study of the hydrolysis of Tabun mimic DCNP in the presence of different amines, aminoalcohols and glycols as potential suitable organocatalysts for DCNP degradation. Experiments were performed in CD3CN in the presence of 5% D2O, which is a suitable solvent mixture to follow the DCNP hydrolysis. These studies allowed the definition of different DCNP depletion paths, resulting in the formation of diethylphosphoric acid, tetraethylpyrophosphate and phosphoramide species as final products. Without organocatalysts, DCNP hydrolysis occurred mainly via an autocatalysis path. Addition of tertiary amines in sub-stoichiometric amounts largely enhanced DCNP depletion whereas non-tertiary polyamines reacted even faster. Glycols induced very slight increment in the DCNP hydrolysis, whereas DCNP hydrolysis increased sharply in the presence of certain aminoalcohols especially, 2-(2-aminoethylamino)ethanol. For the latter compound, DCNP depletion occurred ca. 80-fold faster than in the absence of organocatalysts. The kinetic studies revealed that DCNP hydrolysis in the presence of 2-(2-aminoethylamino)ethanol occurred via a catalytic process, in which the aminoalcohol was involved. DCNP hydrolysis generally depended strongly on the structure of the amine, and it was found that the presence of the OHCH2CH2N moiety in the organocatalyst structure seems important to induce a fast degradation of DCNP.

Regioselective insertion of o-carborynes into the α-C-H bond of tertiary amines: synthesis of α-carboranylated amines.

o-Carboryne can undergo α-CH bond insertion with tertiary amines, thus affording α-carboranylated amines in very good regioselectivity and isolated yields. In this process, the nucleophilic addition of tertiary amines to the multiple bond of o-carboryne generates a zwitterionic intermediate. An intramolecular proton transfer, followed by a nucleophilic attack leads to the formation of the final product. Thus, regioselectivity is highly dependent upon the acidity of α-CH proton of tertiary amines. This approach serves as an efficient methodology for the preparation of a series of 1-aminoalkyl-o-carboranes.

Copper-Filled Electrically Conductive Adhesives with Enhanced Shear Strength

In this study, the effects of diethyl carbitol (diluent) and tertiary amines on the electrical, mechanical, and rheological properties of the Cu-filled polyurethane-based electrically conductive adhesives (ECAs) were investigated. Significant difference could be observed in the electrical resistivity and shear strength of ECA prepared with different amount of diethyl carbitol. Reduced electrical resistivity was found in ECAs prepared with addition of tertiary amines, but no obvious change was observed in the shear strength of the ECA joint. Rheological property of the ECA paste was investigated in order to understand the correlation of the viscosity of ECA paste and electrical resistivity and shear strength of ECA joint. Results revealed that decrease in viscosity of the ECA paste reduced electrical resistivity and enhanced shear strength of ECA joint. A Cu-filled polyurethane-based ECA with considerably low electrical resistivity at the magnitude order range of 10−3 Ω cm, and significantly high shear strength (above 17 MPa) could be achieved.

Generation and Conjugate Additions of o‐Quinone Methides Under Mild Base Conditions: Rapid Synthesis of N‐Substituted Aryl Glycine Derivatives

AbstractA one‐step approach was observed to give N‐substituted aryl glycine derivatives in good to excellent yields (up to 93 %) from (ortho‐hydroxymethyl)aryl benzoates. A cascade mechanism was proposed for the generation and in situ conjugate addition of the ortho‐quinone methides. This mechanism is strongly supported by our subsequent findings that tertiary amines could promote the process. Different functional groups on the (ortho‐hydroxymethyl)aryl benzoates and various amines were investigated to explore the scope of this cascade process. The substituents on the substrates strongly affected the reaction time and yield, and various primary and secondary amines were used as nucleophiles. The addition of tertiary amines enhanced the addition process for less basic nucleophiles.

Selected Reactions of Diethyl (E)‐1‐(bromomethyl)‐2‐cyanovinylphosphonate with Secondary and Tertiary Amines

ABSTRACTAn easy regio‐ and stereoselective synthesis of new nitrogenous molecules 2a–e was successfully realized via an effective coupling reaction of diethyl (E)‐1‐(bromomethyl)‐2‐cyanovinylphosphonate 1 with various secondary amines in methanol. Hence, the use of less and more bulky secondary amines gives rise, respectively, to the successive (SN2′) substitution–isomerization and (SN2) substitution derivatives 2a–c and 2d–e. Moreover, the addition of tertiary amines to 1 in the same reaction conditions, leads exclusively to the rearranged vinyl ether 3 in good yields.

Concentration effects in nucleophilic reactions of tertiary amines in aqueous solutions: The addition of amines to acrylamide monomers in the presence of hydrogen chloride

Studies of the nucleophilic addition of tertiary amines to acrylamide monomers in water in the presence of hydrogen chloride at initial and deeper conversions revealed the presence of special concentration effects, which strongly depended on the structure of the reagents. Viscosity isotherms were studied to show that the reagents in the systems studied experienced active association. The kinetic patterns obtained were explained by changes in the composition and structure of the associates.

Unusual Reversal of Enantioselectivity in the Proline-Mediated α-Amination of Aldehydes Induced by Tertiary Amine Additives

An intriguing reversal in product enantioselectivity accompanied by a change in the kinetic profile is observed in the alpha-amination of aldehydes catalyzed by proline in the presence of organic bases. Implications for the prevailing stereochemical models for proline and related aminocatalytic transformations are discussed.

Efficient Radical Addition of Tertiary Amines to Alkenes Using Photochemical Electron Transfer

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Preparation of Transparent Polyimides and Their Photoinduced Charge Transfer

Polyamide acids (PAA) were prepared from aromatic dianhydrides and aliphatic diamines, which ordinary give high molecular weight polymer due to salt formation during polymerization. Addition of tertiary amines to the PAA solution improves the polymerization reaction due to restriction of the salt formation. Resulting polyimide (PI) was photoirradiated in the presence of tetraphenylporphirine (TPP) as electron donor which transferred electrons to PI, since the partially aliphatic polyimide consists of pyromellitic moieties as strong electron acceptor. The active species generated during the electron transfer process was identified as radical cation of TPP by the laser flash photolysis, whose lifetime is much higher than that in solution. The charge separation by the stabilization of the radical cation is due to strong electron affinity of pyromellitic anhydride moieties of transparent polyimides.

Photochemically induced radical addition of tertiary amines to C=C and C=O double bonds: A green chemistry contribution to organic synthesis

Abstract Photochemically induced electron transfer considerably enriches the redox chemistry of organic molecules. This primary step has been used to produce α-amino alkyl radicals that can be added to various double bonds. The addition to olefinic and carbonyl bonds is discussed. Homogeneous and heterogeneous photocatalysis methods with various electron-transfer sensitizers are described.

Effect of reactant association on addition of tertiary amines to acrylic acid in aqueous solutions

The formation of betaines by the reaction of tertairy amines (N,N-dimethyl-N-2-hydroxyethylamine, N,N-dimethylaminoethyl methacrylate, N-methylmorpholine, N,N-dimethylaminopropionitrile, 1,4-diazabicyclo[2.2.2]octane) with acrylic acid in aqueous solutions in a wide concentration range was studied. The concentration effects observed were interpreted taking into account the association of the starting reagents.

Dispersion of Layered Organosilicates in Isobutylene-Based Elastomers

Abstract Dispersion morphologies of polymer-layered silicate nanocomposites based on either brominated poly(isobutylene-co-para-methylstyrene), BIMSM, or brominated poly(isobutylene-co-isoprene), BIIR, and an organosilicate, dimethylditallow ammonium-exchanged montmorillonite, Cloisite™ 6A, with and without N660 carbon black fillers were examined using SAXS, WAXS, AFM, and TEM. These compounds were prepared using an internal mixer and cured for property measurements. Due to the observed partial orientation of organosilicates and their possible heterogeneous intercalation, degrees of exfoliation and dispersion of organosilicates in BIMSM and BIIR were unable to be characterized and quantified simply by TEM, AFM, or SAXS alone. Instead, using the projected aspect ratio of organosilicates in BIMSM or BIIR, extracted from Gusev-Lusti equation based on measured permeability ratios, was found to provide a relative measure of their dispersion state. Since better dispersion, higher planar orientation, and/or increasing extent of exfoliation lead to higher aspect ratio, this calculated aspect ratio was used as a measure of organosilicate dispersion in BIMSM and BIIR compounds. According to experimentally extracted projected aspect ratios, it was found that BIMSM disperses organosilicates better than BIIR and that carbon black filler does not affect the organosilicate dispersion in BIMSM. Addition of tertiary amines in BIMSM enhances the dispersion of organosilicates, possibly through favorable interactions between organosilicates and quaternary ammonium functionalized BIMSM, resulting in further reduction in permeability.

Thiocarbonyl compounds as regulating reagent in the radical addition of tertiary amines with alkenes using photoelectron transfer conditions

The efficiency of the photoinduced radical addition of tertiary amines to olefinic double bonds is significantly enhanced and the stereoselectivity is influenced when thiocarbonyl compounds are added to the reaction mixture.

Efficient radical addition of tertiary amines to alkenes using photochemical electron transfer

Abstract An efficient photoinduced radical addition of tertiary amine, mainly cyclic derivatives, to electron-deficient alkenes was developed. The reaction was applied to the asymmetric synthesis of the pyrrolizidine alkaloids laburnine and isoretronecanol. The method was then optimized for the addition of a larger variety of tertiary amines, in particular acyclic ones. Radical tandem addition cyclization reactions with unsaturated tertiary amines have also been investigated. A detailed mechanistic study using isotopic labeling enabled the optimization of a corresponding reaction with N,N-dialkylaniline derivatives. The origin of the high reaction stereoselectivity achieved with menthyloxyfuranone was elucidated. The radical addition of tertiary amines was also performed with heterogeneous photocatalysis using inorganic semiconductors as sensitizers.

Influence of the Addition of Tertiary Amine on the Sequence Length of Aromatic Polyamide Copolymers in the Solution Polycondensation

Sequence distribution in the aromatic polyamide copolymerization with 4,4’-diaminodiphenyl ether, 4,4’-diaminodiphenylsulfone and isophthaloyl chloride in N-methyl-2-pyrrolidone was changed from random to some block distribution by adding tertiary amine such as pyridine and triethylamine into the reaction system. The reaction mechanism was examined by some model reactions to clarify the initial stage of polymerization and following conclusion was derived: As reactivity of amino groups in 4,4’-diaminodiphenyl ether became faster than the diffusion of diacid chloride into the reaction solution with the existence of tertiary amine, 4,4’-diaminodiphenyl ether ⁄⁄ isophthaloyl chloride block segments were quickly formed at the initial stage of polymerization to give copolymers with some block tendency.

A New Protocol for the Consecutive α‐ and β‐Activation of Propiolates towards Electrophiles, Involving Conjugate Addition of Tertiary Amines and Intramolecular Silyl Migration

Herein, we present a novel approach for the consecutive alpha- and beta-activation of conjugated alkynes and demonstrate the application of this methodology towards the C-C bond-forming reactions of propiolates. This new concept is based on the 1,4-addition of a tertiary amine to a conjugated alkyne, followed by an aldol-type addition to an aldehyde and subsequent intramolecular silyl migration. This sequential process is generally applicable for 3-trimethylsilylpropiolates. The combination of methyl 3-trimethylsilylpropiolate, 1,4-diazobicyclo[2.2.2]octane (DABCO), and aromatic aldehydes brought about domino-type C-C bond formations to afford highly functionalized olefins as the major products. On the other hand, aliphatic aldehydes, including the sterically demanding aromatic aldehyde, 2,6-dimethylbenzaldehyde, produced alkyne derivatives as the sole products from the reaction, presumably, by the reaction pathway common to the first cases. The intramolecular version of the reaction was successfully applied to the cyclization of trimethylsilylpropiolic esters derived from salicylaldehydes, leading to a new formylcoumarin synthesis. Studies of the reaction mechanisms are also described.