Catalytic olefination of carbonyl compounds. A new versatile method for the synthesis of alkenes

The review is devoted to a new catalytic olefination reaction (COR) discovered by the authors. This is the reaction between N-unsubstituted hydrazones of carbonyl compounds with dihalides CHal₂XY in the presence of copper(i) chloride to give substituted alkenes. Catalytic olefination is versatile. Variation of the carbonyl and olefinating components opens up the way for the synthesis of various classes of unsaturated compounds including those containing functional groups. The reaction mechanism is discussed and a catalytic cycle describing the process is proposed. A model for estimating and predicting the reactivity of halogen-containing compounds in the COR is developed. The relationship between the structure of the carbonyl substrates and their behavior in the title reaction is elucidated.     

A new method for the trifluoromethylation of aromatic compounds

Trifluoromethyl groups attached to aromatic compounds are usually prepared by perchlorinating a methyl group and is subsequently perfluorinated by halogen exchange using a fluorinating agent. In addition to this method, which is also used in industry, there are also a number of different synthesis methods which are however only of limited importance owing to the costly reagents required. The disadvantage of the above-mentioned two-step synthesis lies in the restricted range of application since many of the substituents attached to the aromatic compound hinder the chlorination of the methyl group or they are themselves changed (e. g. methyl, bromine …).By means of a new one-step process, the trifluoromethylation of aromatic compounds is made possible by using the reagent HF/CCl₄.

RH, alkyl, aryl, halogen, phenoxyThe anhydrous hydrofluoric acid acts as a Friedel-Crafts-catalyst, solvent and fluorinating agent. The fange of application of the reaction is discussed. Apart from indicating the influence of the concentration of the reaction components, temperature and pressure, details are also given concerning catalysts and side reactions.     

A new method for the hydroxymethylation of carbonyl compounds

Benzyl chloromethyl ether reacts with carbonyl compounds in the presence of SmI₂ to afford alcohols (I), which are subsequently subjected to hydrogenolysis to yield diols (II).     

A new method for the synthesis of dichlorophosphines

A new method for the synthesis of alkyldichlorophosphines by chlorination of alkylphosphines with phosphorus pentachloride under mild conditions is described.     

A convenient method for the synthesis of α-phenylselenenyl carbonyl compounds

Treatment of ketones or aldehydes with selenium dioxide and diphenyl diselenide in the presence of acid catalyst afforded the corresponding α-phenylselenenyl carbonyl compounds in good yields.     

A new method for the synthesis of N-substituted pyrroles

<正>An unexpected reaction of 10-bromomethyl-12-oxocalanolide A(2) with primary amine was demonstrated and studied. Consequentially,a new method for the preparation of N-substituted pyrroles starting fromγ-halo-α,β-unsaturated ketone was presented.     

A new convenient method for the synthesis of cardiolipin

A novel dichlorophosphate coupling method is developed for the synthesis of the title compound. O-Chlorophenyl dichlorophosphate can be used as a mild phosphorylating reagent to effectively couple with optically active 1,2-O-diacyl-sn-glycerol and 2-O-protected glycerol to assemble cardiolipin bearing different fatty acid chains.     

A new method for the synthesis of 5-amidinobarbiturates

The reactions of 5-[arylamino(methylthio)methylene]pyrimidine-2,4,6(1H,3H,5H)-triones with different aliphatic and aromatic amines were studied. A series of 5-amidinobarbiturates was synthesized. A new and preparatively convenient method for their synthesis appropriate for the use in the combinatorial chemistry was developed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1557–1563, August, 2007.     

A new method for the synthesis of monoalkyl-substituted cyclobutanes

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, p. 2152, September, 1989.     

A new method for the synthesis of macrocyclic ketones

Summary We have described the synthesis of macrocyclic diacetylene ketones by oxidative condensation of aliphatic ,-diacetyiene ketones.     

A new method for the synthesis of 3-hydroxymethylbenzofuran

A new one-step synthesis of 3-hydroxymethylbenzofuran, based on intramolecular cyclization of 2- （methoxymethyl）-2-（2＇-methoxymethyl-4＇-methylphenyl）-butanone I under diluted hydrochloric acid in THF, was developed. The mechanism for this process was investigated via chemical equilibrium shift of tautomer in acidic conditions. The applicability of this new method was studied further in this paper.     

A new method for the synthesis of sulfonated polynaphthylimides

A new method for the synthesis of sulfonated polynaphthylimides has been developed on the basis of the postsulfonation of high-molecular-mass polynaphthylimides with a sulfuric acid-oleum mixture. Sulfonated polymers of this type have been obtained from the polycondensation products of 5-phenylthiophenylene-1,3-diamine with dianhydrides of 1,4,5,8-naphthalenetetracarboxylic acid and 4,4′-(1,4-phenylenedicarbonyl)-bis-naphthalene-1,8-dicarboxylic acid. It has been shown that hydrogen peroxide oxidation of sulfide bridge groups of these polymers in an acidic medium yields high-molecular-mass compounds that contain sulfonic bridge fragments and, therefore, have increased thermal stabilities and enhanced proton conductivities.     

A new method for the synthesis of functionalized maleimides

An effective route to novel maleimides is described, which involves the reaction of an enamine derived from the addition of a secondary amine to a dialkyl acetylenedicarboxylate with an arylsulfonyl isocyanate. These maleimides in solution indicate dynamic NMR because of restricted rotation around the carbon-nitrogen bond, resulting from conjugation of the side-chain nitrogen with the adjacent α,β-unsaturated ester group.     

A new catalytic method for the synthesis of boroxanes

A new Ru-H complex catalyzed O-borylation of boronic acids with vinylboronates leading to boroxane bond formation with evolution of ethylene is described. Under the optimum conditions, when [Ru(CO)Cl(H)(PPh₃)₃] and excess vinylboronate are used, the reaction gives exclusively the corresponding boroxane in high yield. The proposed mechanism of catalysis is supported by the results of the equimolar reaction of Ru-B complex with 1,3,2-dioxaborinan-2-ol.     

A new method for the synthesis of diorganylvinylphosphine oxides

Diorganylvinylphosphine oxides were synthesized in 31–38% yields on heating (50°C) diorganylphosphine oxides with vinyl sulfoxides or divinyl sulfone in the presence of KOH. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1895–1896, October, 1997.