Diaddition Products Research Articles

The Effect of Zn II Coordination on the Addition of 2‐(Aminomethyl)benzimidazole to Acrylonitrile

The effects of NZn coordination, solvent, and pH on the aza-addition reaction between 2-(aminomethyl)benzimidazole (HL) and acrylonitrile were studied. In the absence of ZnII ion, the aza-addition reactions between HL and acrylonitrile (in aqueous media) depended on pH and were not selective. The mono-addition compound {3-[(1H-benzimidazol-2-ylmethyl)amino]propanenitrile} was always obtained in a greater proportion than the di-addition products [3,3′-[(1H-benzimidazol-2-ylmethyl)imino]dipropanenitrile and 3-(2-{[(2-cyanoethyl)amino]methyl}-1H-benzimidazol-1-yl)propanenitrile]. Acrylonitrile selectively reacted at the amine group in the [ZnCl3(H2L)] and [ZnCl2(HL)] complexes in aqueous solutions. Moreover, [ZnCl(HL)2]Cl and [Zn(H2O)2(HL)2]Cl2 complexes yielded mixtures of mono- and di-addition products. In contrast, Zn complexes formed with HL did not react with acrylonitrile in solution in DMSO. The synthesis of mono- and di-addition compounds was studied by 1H and 13C NMR spectroscopy and X-ray diffraction crystallography. Quantum theory of atoms in molecules (QTAIM) computations were used to demonstrate the probable presence of a mono-addition chelate complex.

Utilizing thiol–ene coupling kinetics in the design of renewable thermoset resins based on d-limonene and polyfunctional thiols

Off-stoichiometric manipulations on the initial thiol–terpene composition strongly favor the formation of di-addition product (a) over mono-additions (b + c) when the reaction system contains an equimolar or relative excess of thiol.

Terpene-Based Renewable Monomers and Polymers via Thiol–Ene Additions

Solvent and radical initiator-free addition of thiols to terpenes ((R)-(+)- and (S)-(−)-limonene and (−)-β-pinene) are described as a simple approach to obtain a wide range of alcohol and/or ester functionalized renewable monomers. (R)-(+)-Limonene (1) and (S)-(−)-limonene (2), presenting different reactivity at the endocyclic and exocyclic double bonds, have yielded the monoaddition or diaddition product by simple variation of the thiol feed ratio. In the same manner, (−)-β-pinene (3) derived alcohol and ester monomers have been prepared. The monomers thus obtained have been characterized, and their behavior in polycondensation has been studied. It has been found that long chain diesters or diols, which were synthesized from a castor oil derived platform chemical, are suitable comonomers and result in polycondensates with number-average molecular weights of up to 25 kDa. Thus, terpene/fatty acid-based polyesters were prepared, and their structure–thermal property relationships were studied.

Novel anionic polyaddition of 2-trifluoromethylacrylate by double Michael reaction with ethyl cyanoacetate

Novel fluorinated polymer synthesis with anionic polyaddition by double Michael addition reaction of 2-trifluoromethylacrylate derivatives with ethyl cyanoacetate (ECA) was proposed. Diaddition product of ECA with phenyl 2-trifluoromethylacrylate was yielded in high yield by the catalysis of sodium ethoxide in tetrahydrofuran at 60 °C. Sodium hydroxide catalyzed double Michael addition reaction also produced diaddition product in high yield. Novel anionic polyaddition of 1,4-phenylene bis(2-trifluoromethylacrylate) [CH2C(CF3)COOC6H4OCOC(CF3)CH2] (PBFA) with ECA afforded the polymer of 1.2 × 104 as the highest molecular weight. The isolated polymer gave the polymer of 2.8 × 104 as a molecular weight by the reaction of the isolated polymer with PBFA in the presence of sodium ethoxide; which proved that the polymer end groups were mainly ECA moieties. The reaction mechanism that the proton abstraction from ECA followed by the addition of 2trifluoromethylacrylate was proposed. The reaction of acetylacetone with PBFA was also examined to give the polymer of 7.6 × 103 as the highest molecular weight catalyzed by sodium hydroxide at room temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5698–5708, 2009

Tungstates: Novel heterogeneous catalysts for the synthesis of 5-substituted 1H-tetrazoles

Most heterogeneous catalysts utilized for the formation of 5-substituted 1H-tetrazoles contain zinc as the metal core at the catalytically active site. In this paper, we report that the tungstate MWO 4 (M = Ba, Ca, Zn, Cd, Cu, Na, H) can catalyze the [2+3] cycloaddition reaction of nitriles with sodium azide to produce 5-substituted 1H-tetrazoles in DMF. The catalyst is very efficient, affording good yield of aromatic nitriles and can be reused for several cycles. The mono- and di-addition products from dicyanobenzene can be selectively synthesized, which is a development being reported for the first time. The mechanism of the catalysis may originate from the nitrile group coordinating with the unsaturated W atoms, formed by oxygen vacancies on the surface of solid tungstates.

Characterization of covalent addition products of chlorogenic acid quinone with amino acid derivatives in model systems and apple juice by high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry

High-performance liquid chromatography (HPLC) coupled to electrospray ionization tandem mass spectrometry (ESI-MS(n)) was used to study the covalent interactions between chlorogenic acid (CQA) quinone and two amino acid derivatives, tert-butyloxycarbonyl-L-lysine and N-acetyl-L-cysteine. In a model system at pH 7.0, the formation of covalent addition products was demonstrated for both derivatives. The addition product of CQA dimer and tert-butyloxycarbonyl-L-lysine was characterized by LC/MS(n) as a benzacridine structure. For N-acetyl-L-cysteine, mono- and diaddition products at the thiol group with CQA quinone were found. In apple juice at pH 3.6, covalent interactions of CQA quinone were observed only with N-acetyl-L-cysteine. Taking together these results and those reported by other groups it can be concluded that covalent interactions of amino side chains with phenolic compounds could contribute to the reduction of the allergenic potential of certain food proteins.

Chemoselective anti-Markovnikov hydroamination of α,β-ethylenic compounds with amines using montmorillonite clay

The catalytic activity of montmorillonite clays as a catalyst for the hydroamination of α,β-ethylenic compounds with amines was tested. Aniline and substituted anilines reacted with α,β-ethylenic compounds in the presence of catalytic amount of commercially available clay to afford exclusively anti-Markovnikov adduct in excellent yields. Aniline reacted with ethyl acrylate to yield only anti-Markovnikov adduct N-[2-(ethoxycarbonyl)ethyl]aniline (mono-addition product). No Markovnikov adduct ( N-[1-(ethoxycarbonyl)ethyl]aniline and double addition product N, N-bis[2-(ethoxycarbonyl)ethyl]aniline were formed under selected reaction conditions. For a better exploitation of the catalytic activity in terms of increased activity and improved selectivity for the mono-addition product, the reaction parameters were optimized in terms of temperature, solvent, reactant mole ratio. Under optimized reaction conditions, montmorillonite clay K-10 showed a superior catalytic performance in the hydroamination of ethyl acrylate with aniline with a conversion of aniline to mono-addition product (almost 100% chemoselectivity) with a high rate constant 0.3414 min −1 compared to the reported protocols. The dependence of conversion of aniline over different types of montmorillonite clays (K-10, K-20, K-30, Al-Pillared clay and untreated clay) has also been discussed. The activities of clay for the hydroamination of different aromatic and aliphatic amines have also been investigated. Under harsh reaction conditions (increased temperature and long reaction time) small amounts of di-addition products were observed. The kinetics data has been interpreted using the initial rate approach model.

Cyclization of 5-hexenyl radicals from nitroxyl radical additions to 4-pentenylketenes and from the acyloin reaction

Photochemical Wolff rearrangements were used to form 5-substituted-4-pentenylketenes 1a–1d (RCH=CHCH2XCH2CH=C=O: 1a R = H, X = CH2; 1b R = Ph, X = CH2; 1c R = c-Pr, X = CH2; 1d R = H, X = O), which were observed by IR at 2121, 2120, 2119, and 2126 cm–1, respectively, as relatively long-lived species at room temperature in hydrocarbon solvents. These reacted with the nitroxyl radical tetramethylpiperidinyloxyl (TEMPO, TO·) forming carboxy-substituted 5-hexenyl radicals 3, which were trapped by a second nitroxyl radical forming 1,2 diaddition products 4a–4d. On thermolysis, 4a–4d underwent reversible reformation of the radicals 3, which underwent cyclization forming cyclopentanecarboxylic acid derivatives 6 or 11 as the major products. However, in the case of 1b, the cyclopentane derivative was formed reversibly and on prolonged reaction times the only product isolated was PhCH=CH-(CH2)4CO2H (8b) from hydrogen transfer to Cβ and cleavage of the TEMPO group. Cyclopropylcarbinyl radical ring opening in the cyclized radical 5c from 1c led to the 2-(4-N-tetramethylpiperidinyloxybut-1-enyl)cyclopentane derivative 11 as the major product. In a test for 5-hexenyl radical ring closure in the radical anion intermediate of the acyloin condensation, the ester CH2=CH(CH2)3CO2Et (12a) gave the acyloin 13a (76%) as the only observed product, while PhCH=CH(CH2)3CO2CH3 (12b) with Na in toluene gave 21% of the acyloin product 13b and 42% of 2-benzylcyclopentanol (15) from cyclization of the intermediate radical anion.Key words: ketenes, free radical cyclization, TEMPO, acyloin condensation.

DTBB-Catalysed dilithiation of styrene and its methyl-derivatives: introduction of two electrophilic reagents

The reaction of styrene and some methyl-substituted styrenes 1 with lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB) in the presence of several electrophiles [Me3SiCl, Me2CO, Et2CO, (CH2)5CO, Pr2CO], in THF, at temperatures ranging from −78 to 0°C, gave, after hydrolysis, products 2 resulting from addition of lithium to the olefinic double bond and successive trapping with the electrophilic reagent. When a carbonyl compound was used as electrophile, mixtures of the monoaddition–reduction compounds 3 and 4 were obtained as by-products, which could be easily separated from the diaddition products 2.

Diketo compounds with (trifluoromethyl)trimethylsilane: double nucleophilic trifluoromethylation reactions.

Reactions of various diketo compounds with (trifluoromethyl)trimethylsilane (Me3SiCF3) in the presence of catalytic amounts of cesium fluoride have been studied. gamma-Ketoesters, CH3COCH2CH2CO2R (R = Et, Bu), were reacted with 2 equiv of Me3SiCF3 at room temperature to give CH3C(OH)(CF3)CH2CH2COCF3 in good yield after hydrolysis. alpha-Diketones, R1COCOR2 (R1 = R2 = Ph; R1 = Ph, R2 = Me; R1 = R2 = Me; R1 = Me, R2 = Et), when reacted with Me3SiCF3, formed 1:1 or 1:2 addition products depending on the reaction conditions and stoichiometry used. Reactions of diones CH3COXCOCH3 (X = -CH2CH2-, -C6H4C6H4-, -CH2-) with Me3SiCF3 also led to the formation of the mono- or diaddition products depending on reaction conditions. With various kinds of substituted arylglyoxals, 2 equiv of Me3SiCF3 produced monoaddition products in 70-75% yield and diaddition products in 5-10% yield. One of the monoalcohols and two of the diols have been characterized by single-crystal X-ray analysis, and the presence of inter- and intramolecular hydrogen bonding has been confirmed.

Characterization of Products from the Reactions of Dopamine Quinone withN-Acetylcysteine

The reactions between electrochemically prepared dopamine (DA) quinone andN-acetylcysteine (NACySH), a protein model nucleophile, have been investigated at pH 7 and pH 2. Major products were purified by semipreparative reversed-phase liquid chromatography and identified by mass spectrometry and nuclear magnetic resonance spectroscopy to be nucleophilic addition products of the quinone with NACySH. The principal product is the monoaddition adduct of the quinone at C(5) of the ring, 5-S-(N-acetylcysteinyl)dopamine. The diaddition adduct of the quinone at C(2) and C(5) of the ring, 2,5-S,S′-di-(N-acetylcysteinyl)dopamine, and the monoaddition product at C(2) of the ring, 2-S-(N-acetylcysteinyl)dopamine, are produced to lesser extents. The relative molar ratio of 2-S-(N-acetylcysteinyl)dopamine, 5-S-(N-acetylcysteinyl)dopamine, and 2,5-S,S′-di-(N-acetylcysteinyl)dopamine produced at pH 7 is approximately 8:59:33, whereas at pH 2 the ratio is 10:89:1. The uv/vis spectroscopic analysis shows that the two monoaddition products have maxima at 258 and 294 nm, whereas the diaddition product has a maximum at 276 nm and a shoulder at 302 nm. Cyclic voltammetry and chronoamperometry demonstrate that these adducts are oxidized more readily than DA, which causes the anodic current for the oxidation of DA in the presence of NACySH to be kinetically controlled by the rates of the addition reactions. A reaction scheme is proposed for the formation of these products.

Oxidation of ketones by ferric perchlorate in the presence of conjugated dienes to hexahydrofuro[2,3-b]furans and 1,6-dioxaspiro[4,4]nonanes

Iron(III) perchlorate nonahydrate (FEP) in acetonitrile in the presence of conjugated dienes oxidizes carbonyl compounds (aldehydes and ketones) to α,α-diaddition products hexahydrofuro[2.3-b]-furans 3, in moderate yield (nine examples). α,α-Disubstituted ketones afford the α,α′-diaddition products 1,6-dioxaspiro[4,4]nonanes 4 or monoaddition products 6 and 7. The isomer distribution and the influence of the reaction conditions are discussed based on selective oxidative deprotonation of the carbonyl compound by iron(III) and addition of α-carbonylalkyl radicals to conjugated olefins.

The friedel-crafts reaction of acid chlorides with ethene ; Di-addition and molecular rearrangement

Acid chlorides, complexed with excess aluminium chloride, reacted with ethene to form 3-methyl-2-buten-1-ones, i.e. rearranged di-addition products having a terminal isoprenoid skeleton, together with the usual β-chloropropanones. The latter were the sole products in the absence of excess catalyst. Acid chlorides containing a suitably situated π-system underwent intramolecular cyclization, e.g. 2-phenylcyclopropanecarbonyl chloride ( 10) cyclized to 3,4-benzobicyclo[3.1.0]hexan-2-one ( 11).

Etude de la diaddition de l'acétate d'allyle sur les télogènes chlorofluorés possédant deux groupements CCl3 en extrémité de chaîne

AbstractThe redox catalyzed addition of compounds such as Cl3CCF2CCl3 and Cl3CCF2CCl2CH2CHClCH2OCOCH3 to allyl acetate was studied with the purpose of obtaining telechelic products. RuCl2[P(C6H5)3]3 was used as catalyst, and its action was compared to that of cooper‐ or iron‐based catalysts. The products were isolated and their structures studied by means of 13C, 19F and 1H NMR spectroscopy. The reaction mechanism was studied to improve the yield of the diaddition product for its utilisation as monomer in polycondensation reactions. It was found that the low reactivity for a second addition is not due to the presence of a chlorine atom in β‐position of the acetate function. When allyl acetate was replaced by allyl bromide or chloride in the first addition, the second addition to allyl acetate occurred normally.

Haloaldehyde Polymers XXXIII. Polymerization of Chloral with Chiral Anionic Initiators. Stereochemistry of Initiation

The addition of trichloroacetaldehyde (chloral) to an equimolar amount of the lithium alkoxide of (−)borneol gave, after acetylation with acetic anhydride, diastereomers which were separated by gas chromatography. The products resulted from meso and racemic addition of the (−)borneoxide on chloral. Di-addition products with two chloral residues were also isolated but the individual isomers were not identified. Similar studies with the alkoxides of racemic alcohols were also undertaken. An analysis of their addition products suggested that the individual (R) and (S) components of the chiral alkoxides added chloral in a stereochemically preferred manner. This preference was most pronounced for those alkoxides which possess a high degree of steric bulk around their chiral carbon atoms.

Reaction of azinium cations. 5. Addition of water and methanol to 1,4-diazinium cations in the presence of bases. equilibrium constants and PMR spectra of the mono- and diadducts

The PKR+ values and equilibrium constants for the addition of hydroxide ions to 1,4-diazinium ions were determined by spectrophotometry. The ratios 1∶1 and 1∶2 of the methoxyl adducts of the 1,4-diazinium ions in the sodium methoxide-methanol-D4 system and the equilibrium constants for the transformations of the mono-adducts into the diaddition products were determined by PMR spectroscopy.

ChemInform Abstract: Hydrophosphorylation of Alkines with Phosphinous Acids.

AbstractDibutylphosphinigsäure (I) reagiert mit den Alkinen (II) in Gegenwart von Dibenzoylperoxid unter Addition an die Dreifachbindung zu Gemischen der cis‐/trans‐ungesättigten Phosphinoxide (III).

Reaktivität und Elektronenstruktur porphinoider Nickelkomplexe

Reactivity and Electronic Structure of Porphine‐type Nickel ComplexesThe electronic structure of the porphine‐type hexaaza[16]annulene‐nickel dikation 1′ as well as its mono‐ and diaddition products 2′ and 3′ (Scheme 2) has been considered by an extended Hückel treatment (SCCC‐MO including charge iteration on the central metal atom). Correlations between calculated data and reactivity of the porphinoid compounds 1, 2 and 3 (Scheme 1) are discussed.

Rhodium (I)‐katalysierte Reaktionen der [2+4]‐Cycloaddukte aus 3,4‐Dimethoxyfuran und Acetylendicarbonsäure‐estern

[2+4]‐Cycloaddition Products of 3,4‐Dimethoxyfuran with Acetylenedicarboxylates and Their Transformations under the Influence of Rhodium(I) Catalysts3,4‐Dimethoxyfuran (1) readily reacts with acetylenedicarboxylates (2) at room temperature in a [2+4]‐cycloaddition to give a mono‐(3) and several di‐addition products. 90% of the latter consists of the endo‐exo compound 4. Under the influence of catalytic amounts of [Rh(CO)2Cl]2 the mixture of mono‐ and di‐adducts in methanolic solution is smoothly transformed into endo‐5,5,6‐trimethoxy‐7‐oxabicyclo [2.2.1]hept‐2‐ene‐2,3‐dicarboxylateAlle Verbindungen sind racemisch. Die Formeln stellen jeweils nur ein Enantiomeres dar. (5) , 3‐hydroxy‐4,5‐dimethoxyphthalate ( 6 ) and (I R *, 2 S *, 4 R *, 5 R *, 7 R *, 11 R *, 12 R *) ‐5,8,8,9,12‐pentamethoxy‐3,6‐dioxatetracyclo [5.3.1.1 2,5 . 0 4,11 ]dodec‐9‐ene‐1,11‐dicarboxylate ( 7 ).

Addition of vinylchlorosilanes to binuclear aromatic compounds

Some binuclear aromatic compounds were alkylated with vinylmethyldichlorosilane in the presence of AlCl3 to give both mono- and di-addition products.