Base-Catalyzed Intramolecular Cycloaddition of Dialkyl(4-hydroxybut-2-yn-1-yl)[3-(4-bromophenyl)prop-2-yn-1-yl]ammonuim Chlorides and Recyclization of the Products

Russian Journal of Organic Chemistry - Dialkyl(4-hydroxybut-2-yn-1-yl)[3-(4-bromophenyl)prop-2-yn-1-yl]ammonium chlorides in the presence of 2 equiv of potassium hydroxide at room temperature...     

Intramolecular photoreactions of 6-(ω-alkenyl)-4-methoxy-2-pyrones

6-(ω-Alkenyl)-2-pyrones 3a-c and 8a, b were prepared and the photochemical reactions were investigated. Photosensitized reactions of 3b, c gave intramolecular [2+2]-cycloadducts 11b, c as tricyclic lactones, site-and regio-specifically. They are not frontier-orbital-controlled adducts. On the other hand, 3a, 8a, b afforded cyclobutenecarboxylic acids, 10a, 14a, b , respectively. The end-ester group at the side-chain is thought not to be effective for the intramolecular phptoaddition.     

Stereoselective Synthesis of Dialkyl 2-(Arylsulfonylamino)-3-(dialkoxyphosphoryl) Succinates by Reaction of Trialkyl(aryl) Phosphites,Dialkyl Acetylenedicarboxylates,and Arylsulfonamides

A three-component reaction of trialkyl(aryl) phosphites, dialkyl acetylenedicarboxylates, and arylsulfonamides is described as a simple and efficient route for the synthesis of dialkyl 2-(arylsulfonylamino)-3-(dialkoxyphosphoryl)-succinates in good yields.

Intramolecular Cyclization of Mercaptomethyl Derivatives of Alkyl 3-(Furyl)-3-(diethoxyphosphoryl)acrylates

Russian Journal of General Chemistry - Alkyl E-3-(furyl)-3-(diethoxyphosphoryl)acrylates containing a mercaptomethyl group in the position of the furan ring adjacent to the alkene moiety are easily...     

Intramolecular cyclization of amido acids into pyrrolidinothieno(or [1]benzothieno)[3]azepinediones

The synthesis of pyrrolidino[2,1-b]thieno[3,2(2,3)-f][3]azepinediones 7a,b and pyrrolidino[2,1-b]-[1]benzothieno[3,2(2,3)-f][3]azepinediones 7c,d are described starting from thiophenes or [1]benzothio-phenes acetic acids. Their selective reduction using triethylsilane led to the corresponding azepinones 17a-d.     

Cyclization of 2-(1′-alkyl-2′-alkenyl)anilines in polyphosphoric acid

The cyclization of 2-alkenylarylamines in polyphosphoric acid (PPA) with 1,2 and 1,3 shifts of the -alkyl substituent of the alkenyl fragment leads to the formation of indoline and indane compounds. Cis- and trans-stereoisomers of 2-methyl-4-ethyl-1-aminoindane formed without displacement of the -substituents as well as 2-methyl-2-propylindoline are obtained from 2-(1 -methyl-2 -pentenyl)-aniline.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2811–2814, December, 1990.     

Photocatalyzed Intramolecular [2+2] Cycloaddition of N-Alkyl-N-(2-(1-arylvinyl)aryl)cinnamamides

N-Alkyl-N-(2-(1-arylvinyl)aryl)cinnamamides are converted into natural product inspired scaffolds via iridium photocatalyzed intramolecular [2+2] photocycloaddition. The protocol has a broad substrate scope, whilst operating under mild reaction conditions. Tethering four components forming a trisubstituted cyclobutane core builds rapidly high molecular complexity. Our approach allows the design and synthesis of a variety of tetrahydrocyclobuta[c]quinolin-3(1H)-ones, in yields ranging between 20–99 %, and with excellent regio- and diastereoselectivity. Moreover, it was demonstrated that the intramolecular [2+2]-cycloaddition of 1,7-enynes—after fragmentation of the cyclobutane ring—leads to enyne-metathesis-like products.     

Trimethylchlorosilane-Catalyzed Intramolecular Cyclization of 2-(2-Benzylideneaminoethyloxy)-1-phenylbenzo[e]-1,3,2-azaoxaphosphorin-4-one

Russian Journal of General Chemistry - A catalytic effect of trimethylchlorosilane on the intramolecular cyclization of 2-(2-benzylideneaminoethyloxy)-1-phenylbenzo[e]-1,3,2-azaoxaphosphorin-4-one...     

New Cycloadditon Reaction of 2-Chloroprop-2-enethioamides with Dialkyl Acetylenedicarboxylates: Synthesis of Dialkyl 2-[4,5-bis(alkoxycarbonyl)-2-(aryl{alkyl}imino)-3(2H)-thienylidene]-1,3-dithiole-4,5-dicarboxylates

The 1,3-dipolar cycloaddition of 1,2-dithiole-3-thiones with alkynes to form 1,3-dithioles is one of the most studied reactions in this class of polysulfur-containing heterocycles. Nucleophilic substitution of chlorine atoms in dimethyl 2-(1,2-dichloro-2-thioxoethylidene)-1,3-dithiole-4,5-dicarboxylate, which was obtained by addition one molecules of DMAD to 4,5-dichloro-3H-1,2-dithiole-3-thione, led to a series of 2-chloro-2-(1,3-dithiol-2-ylidene)ethanethioamides. Cycloaddition reaction of 2-chloro-2-(1,3-dithiol-2-ylidene)ethanethioamides with activated alkynes led to the unexpected formation of 2-(thiophen-3(2H)-ylidene)-1,3-dithioles via new intermediate, 1-(1,3-dithiol-2-ylidene)-N-phenylethan-1-yliumimidothioate. Structure of dimethyl 2-(4,5-bis(methoxycarbonyl)-2-(phenylimino)thiophen-3(2H)-ylidene)-1,3-dithiole-4,5-dicarboxylate was finally proven by single crystal X-ray diffraction study. Optimized reaction conditions and a mechanistic rationale for the 1,3-dipolar cycloaddition of novel intermediate are presented.     

Palladium(II)-assisted conversion of a 2-alkenyl sulfone into a 3-acetoxy(or chloro)-1-alkenyl sulfone

2-alkenyl p-tolyl sulfone was converted into the corresponding 3-acetoxy-1-alkenyl p-tolyl sulfone via a π-allyl palladium complex which underwent regiospecific attack of a nucleophile, acetate ion, and the reaction conditions for predominant formation of 3-chloro-1-alkenyl p-tolyl sulfone are also described.     

Intramolecular Cyclization of 4-Isocyanato-3-(2-naphthyl)-1-phenylpyrazole Under Friedel-Crafts Reaction Conditions

4-Isocyanato-3-(2-naphthyl)-1-phenylpyrazole cyclized under the influence of AlCl₃ to give 2H-benzo[h]pyrazolo[4,3-c]isoquinoline.     

Synthesis and Antimicrobial Activity of New Dialkyl(diaryl)-2-(5-chloro-2-hydroxyphenyl)-2-(phenylethenyl)pentylphosphonium Salts

New dialkyl(diaryl)-2-(5-chloro-2-hydroxyphenyl)-2-(phenylethenyl)pentylphosphonium salts bearing various substituents at the phosphorus atom were synthesized. Antimicrobial activity of the salts obtained was estimated. Derivatives with 2-methoxyphenyl substituents at the phosphorus atom are most active against grampositive bacteria. Herewith, dibenzyl-substituted phosphonium derivatives possess the best antifungal activity.     

Intramolecular 1,5-Hydride Shift in Products of Stevens 3,2-Rearrangement of Ammonium Salts Containing 3-Phenyl-2-propynyl Group

In products of Stevens 3,2-rearrangement of ammonium salts containing alongside alkoxycarbon- ylmethyl also 3-phenyl-2-propynyl group an intramolecular 1,5-hydride shift is observed resulting in immonium salts which transform into aminoesters of enamine structure. The hydrolysis of the latter provides the lower aliphatic aldehydes and the corresponding aminoesters. An acid treatment of the reaction mixture affords a mixture of hydrogenated and nonhydrogenated esters of α-ketoacids originating from the mixture of 1,3-diene aminoesters. At treating with concn. HCl of the obtained mixture the nonhydrogeneted ketoester undergoes cyclization into 4-methyl-3-phenyl-2-buten-1,4-olide.     

Conformational Equilibrium of 4-Hydroxy- and 4-Acetoxy-4-(3-aryloxy-1-propynyl)-1-(2-ethoxyethyl)piperidinium Salts in Solution

4-Hydroxy- and 4-acetoxy-4-(3-aryloxy-1-propynyl)-1-(2-ethoxyethyl)piperidine hydroclorides in aprotic solvents give rise to equilibrium mixtures of two epimers. In the case of the acetoxy derivatives (in CDCl₃) the equilibrium is displaced toward the less stable epimer. This may be due to considerable contribution of the skewed boat conformer with intramolecular hydrogen bond.     

Intramolecular Cyclization of 1-Benzyl-2-(nitromethylene)pyrrolidines in Triflic Acid

1-Benzyl-2-(nitromethylene)pyrrolidines in triflic acid undergo intramolecular cyclization to afford the corresponding 2,3-dihydro-1H-pyrrolo[1,2-b]isoquinolinium triflates and/or 10-amino-2,3-dihydro-1H-pyrrolo[1,2-b]isoquinolinium triflates, depending on the nature of the aromatic substituent. Structures of products and reaction mechanisms are discussed.     

Synthesis,Intramolecular Cyclization,and Analgesic Activity of Substituted 2-[2-(Furancarbonyl)hydrazinylydene]-4-oxobutanoic Acids

Russian Journal of General Chemistry - A method was proposed for the synthesis of substituted 2-[2-(furan-2-carbonyl)hydrazinylidene]-4-oxobutanoic acids by the reaction of...     

Regioselectivity of Intramolecular Electrophilic Cyclization of 2-(Alkenylsulfanyl)thieno[2,3-d]pyrimidin-4(3H)-ones with p-Methoxyphenyltellurium Trichloride

Russian Journal of Organic Chemistry - 3-Phenyl-2-(prop-2-en-1-ylsulfanyl)-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one reacted with 4-methoxyphenyltellurium trichloride in a...     

Erratum to: Synthesis and Antimicrobial Activity of New Dialkyl(diaryl)-2-(5-chloro-2-hydroxyphenyl)-2-(phenylethenyl)-pentylphosphonium Salts

Russian Journal of General Chemistry - The row in the table on p. 1802 for compound 8a should be as follows:     

S-烃基-1-烃基-3-[4-(苯并咪唑-2-巯基)苯基]异硫脲的合成及其iNOS抑制活性

以2-巯基苯并咪唑(1)为原料,经缩合和还原得到2-(4-氨基苯硫基)苯并咪唑(3),再与异硫氰酸苯甲酰酯或异硫氰酸烃基酯反应得到取代硫脲(5和7),最后与卤代烃反应得到20个新的S-烃基-1-烃基-3-[4-(苯并咪唑-2-巯基)苯基]异硫脲化合物(6和8),其结构经IR,¹HNMR,MS及元素分析确证.初步的药理试验表明,20个目标化合物均有不同程度的iNOS抑制活性,其中化合物6b,8d和8f的iNOS抑制活性与阳性对照药氨基胍相当.