Friedel-Crafts Alkylation of Alkenes: Ethylaluminum Sesquichloride Induced Alkylations with Alkyl Chloroformates

The formal addition of propane to nonactivated double bonds can be achieved with isopropyl chloroformate (2) in the presence of Et(3)Al(2)Cl(3). Thus, a 1:1 mixture of 10-isopropyloctadecanoic acid (3) and the 9-regioisomer is formed from oleic acid (1). The reaction may also be carried out with 1-alkenes by the addition of triethylsilane as a hydride donor.     

Alkyl 3-Nitroacrylates in Reactions with Semicarbazide

Russian Journal of General Chemistry - The reactions of alkyl-3-nitroacrylates with semicarbazide as representative of polynitrogen nucleophiles proceeds at room temperature in a solution of...     

Alkyl 3-Nitroacrylates in Reactions with Substituted Hydrazines

Russian Journal of General Chemistry - The reactions of alkyl 3-nitroacrylates with representatives of aryl(hetaryl) carboxylic acid hydrazides and substituted phenylhydrazines were studied. It was...     

Iron-Catalyzed Cross-Coupling Reactions of Alkyl Grignards with Aryl Chlorobenzenesulfonates

Aryl sulfonate esters are versatile synthetic intermediates in organic chemistry as well as attractive architectures due to their bioactive properties. Herein, we report the synthesis of alkyl-substituted benzenesulfonate esters by iron-catalyzed C(sp²)–C(sp³) cross-coupling of Grignard reagents with aryl chlorides. The method operates using an environmentally benign and sustainable iron catalytic system, employing benign urea ligands. A broad range of chlorobenzenesulfonates as well as challenging alkyl organometallics containing β-hydrogens are compatible with these conditions, affording alkylated products in high to excellent yields. The study reveals that aryl sulfonate esters are the most reactive activating groups for iron-catalyzed alkylative C(sp²)–C(sp³) cross-coupling of aryl chlorides with Grignard reagents.     

Reactions of O2 --Containing Supramolecules with Alkyl Halides

Formation of O₂ ^--containing supramolecules generated from the system 18-crown-6-KO₂ and electrochemically (tetraethylammonium superoxide) and the kinetics of the reactions of the generated O₂ ^- with alkyl halides in acetonitrile were studied conductometrically and UV-spectrophotometrically; the kinetic parameters of the processes were determined. The E2 mechanism was suggested for the reaction.     

Alkylation-Terminated Catellani Reactions Using Alkyl Carbagermatranes

The Catellani reaction has received substantial attention because it enables rapid multiple derivatization on aromatics. While using alkyl electrophiles to achieve ortho-alkylation was one of the earliest applications of the Catellani reaction, ipso-alkylation-terminated reactions with β-H-containing reactants has not been realized to date. Herein, we report alkylation-terminated Catellani reaction using alkyl carbagermatranes (abbreviated as alkyl- Ge ) as nucleophiles. The reactivity of alkyl- Ge and alkyl-B(OH)₂ in this reaction is discussed. This approach enables efficient dialkylation with β-H-containing reactants, which was previously inaccessible by Catellani reactions.     

Intramolecular and Intermolecular Schmidt Reactions of Alkyl Azides with Aldehydes

Despite recent advances in the use of alkyl azides in ring expansion reactions of ketones, there has been little work done on the corresponding chemistry of aldehydes. In the present study, the Lewis acid-promoted reactions of alkyl azides with aldehydes were studied in both intermolecular and intramolecular contexts. The intramolecular reactions of azidoalkyl aldehydes in which the azide and carbonyl groups were separated by 2-5 carbons were examined. Although the examples having the shortest tether failed (3-azidopropanals), each of the other systems gave good yields of either NH-substituted lactams (resulting from hydride migration in the initially formed azidohydrin adduct) or formamides (alkyl migration). The product formed was dependent on the chain length of the starting azido aldehyde. The intermolecular reactions were less efficient, requiring TiCl₄ promotion for even moderate yields, and in each case gave mixtures of products resulting from hydride and alkyl migration.     

Alkyl 3-Bromo-3-nitroacrylates in Reactions with Aliphatic Alcohols

Russian Journal of General Chemistry - The reactions of alkyl 3-bromo-3-nitroacrylates with aliphatic alcohols at reflux led to the formation of O-adducts—alkyl...     

Photochemical Reactions of Alkyl Phenylglyoxylates(1)

Three new photoproducts, ethyl O-benzoyl mandelate (5a), ethyl O-acetylmandelate (6a), and biphenyl triketone (7a) are isolated and identified in the reactions of ethyl phenylglyoxylate (1a) in benzene. Quantum yields and initial rate constants of product formation are shown to be concentration dependent. For the formation of carbonyl product 3 at lower starting material concentrations (<0.01 M), quantum yields greater than 1 are observed. Variations in the quantum yields as a function of reaction time are due to the accumulation of alpha-hydroxyphenyl ketene (D). The relative reactivities of triplet excited states of phenylglyoxylates 1 and phenyl ketones are compared. A mechanism involving both intramolecular gamma-H abstraction and intermolecular H abstraction, which leads to radical chain reaction, is proposed. Rate constants for intramolecular gamma-H abstraction (k(N)) and intermolecular H abstraction (k(I)) of methyl phenylglyoxylate (1d) are measured.     

Hydroxide-Promoted Elimination Reactions: Alkyl Halides as Substrates

Potassium hydroxide, in presence of tetraethyleneglycol dimethyl ether, easily abstracts hydrogen chloride or hydrogen bromide from secondary and tertiary halides, but primary chlorides lead to roughly equal amounts of elimination and substitution products. Addition of small quantities of trimethylamine, however, starts a catalytic cycle involving ammonium salts and favoring alkene formation. The described method appears to be more efficient and more economic than any other non-pyrolytic process.     

Sulfur Transfer Reactions of Tetrathiomolybdate in Water: Synthesis of Alkyl Disulfides from Alkyl Halides

Abstract: Reaction of a number of alkyl halides with tetrathiomolybdate in water as the solvent affords the corresponding disulfides in good yields.     

2，5－二甲氧基苯基烷基酮与t－BuMgCl反应的机理研究

２，５－二甲氧基苯基烷基酮１_（ａ－ｄ）（烷基分别为甲基、乙基、异丙基和叔丁基）与ｔ－ＢｕＭｇＣｌ反应后，主要生成了１，２－加成产物、１．６－共轭加成产物及还原产物，产物及其分布在不同程度上受酮的结构、反应介质以及金属镁中过渡金属杂质的含量等因素的影响。据此，提出了反应的可能机理。     

2,5-二甲氧基苯基烷基酮与t-BuMgCl反应的机理研究

2,5-二甲氧基苯基烷基酮1_(a-d)(烷基分别为甲基、乙基、异丙基和叔丁基)与t-BuMgCl反应后,主要生成了1,2-加成产物、1.6-共轭加成产物及还原产物,产物及其分布在不同程度上受酮的结构、反应介质以及金属镁中过渡金属杂质的含量等因素的影响。据此,提出了反应的可能机理。     

Redox Reactions Of Polyhydride Complexes of Rhenium: electrochemistry and Reactions With Alkyl Isocyanides

The dark red octahydride complex of dirhenium, Re₂H₈(PPh₃)₄, undergoes a reversible one-electron oxidation to the blue mono-cation [Re₂H₈(PPh₃)₄]⁺ (E_{$\text{buit;1}\text{2}$} ?0.24 V vs. SCE by cyclic voltammetry). The X-band ESR spectrum of a dichloromethane glass (?160°C) containing the monocation is in accord with the HOMO being a delocalized metal-based orbital. Treatment of the heptahydrides ReH₇(PR₃)₂ (PR₃ = PPh₃ or PEtPh₂) with C₆H₁₁NC or Me₃CNC in the presence of KPF₆ leads to the elimination of hydrogen and the formation of [Re(CNR)₄(PR₃)₂]PF₆. Electrochemical oxidation of ReH₅(PPh₃)₂L (L = PPh₃, PEt₂Ph, pyridine, piperidine or cyclohexylamine) activities these molecules to attack by RNC to afford rhenium(I) species     

取代苯基烷基酮与叔丁基氯化镁反应的机理研究

通过EPR技术观察到一系列典型的烷基或甲氧基取代的苯基烷基酮ArCOR(Ar=2,5-二甲基苯基(1);2,5-二甲氧基苯基(2);4-叔丁基-2,5-二甲氧基苯基(3))与t-BuMgCl反应中形成的自由基阴离子中间体[ArC(R)OMgCl]。产物分析表明,反应主要生成还原产物[ArCH(R)OH]和1,2-加成产物[ArC(R)(t-Bu)OH]。降低溶剂极性及反应温度都有利于还原产物的生成。对上述反应的可能历程作了简单讨论。     

Role of Radical Elimination Reactions with Concerted Fragmentation in the Chain Decomposition of Alkyl Nitrates

The reactions X? + HCR₂ONO₂ → XH + R₂C=O + ?NO₂ are very exothermic due to the cleavage of the weak N?O bond and the formation of the energy-intensive C=O bond. The quantum chemical calculation of the transition state of these reactions for X? = Et? and EtO? used as examples showed that they actually proceed in one elementary act as eliminations with concerted fragmentation. The kinetic parameters were estimated within the framework of the intersecting parabolas model; the parameters allow the calculation of the activation energy and rate constant from the enthalpy of the above reaction. For a series of reactions involving the Et?, EtO?, RO?₂, and ?NO₂ radicals, on the one hand, and a number of alkyl nitrates, on the other, their enthalpies, activation energies, and rate constants were calculated. Based on the data obtained, new kinetic schemes of the chain decomposition of alkyl nitrates involving eliminations with fragmentation were proposed.     

Three-Component,Four-Molecule,Ru-Catalyzed Cascade Reactions of Indoles and Alkyl Bromides with Sodium Nitrite

Abstract

An operationally simple domino approach for the ruthenium-catalyzed synthesis of (E)-2,3′-bi(3H-indol)-3-one O-alkyl oximes by the region- and stereoselective three-component, four-molecule reactions of indoles with sodium nitrite and alkyl bromides under mild reaction condition in dimethylformamide is described. Remarkably, multiple bonds including C?C, C=N, and C?O bonds were conveniently formed in one pot. The reaction is tolerant to air and is atom economical, in accordance with the concept of modern green chemistry.