Synthesis of substituted 3-arylpiperidines and 3-arylpyrrolidines by radical 1,4 and 1,2-aryl migrations

A route to 3-arylpiperidines and 3-arylpyrrolidines involving radical 1,4- and 1,2-aryl migrations has been explored. For the piperidines, the first route requires a xanthate addition to an N-allylarylsulfonamide, followed by acetylation and treatment with lauroyl peroxide to give the corresponding 1,4-aryl transfer product. This compound can be converted into the desired piperidine derivative following acidic hydrolysis. For the second approach to piperidines, addition of an α-keto xanthate to olefins of type 14 causes 1,2-aryl migration leading to an α,β-unsaturated ester, which can be converted into a piperidine by the action of ammonia or a primary amine and sodium cyanoborohydride. Substituted 3-arylpyrrolidines can be obtained by simply starting with an α-amido substituted xanthate.     

Synthesis of novel C2-aryl pyrrolobenzodiazepines (PBDs) as potential antitumour agents

Three novel C2-aryl substituted pyrrolobenzodiazepines (PBDs) have been synthesised and evaluated in a number of cell lines revealing selective cytotoxicity at the sub-nanomolar level towards melanoma and ovarian cancer cell lines.     

Synthesis and structural study of novel 5-aryl substituted 2-amino-4,7-dioxopyrido[2,3-d]pyrimidines

The tide compounds 4a-c have been prepared in a one-step procedure from 2,4-diamino-6-hydroxy-pyrimidine (1) and the corresponding arylidene substituted Meldrum's acids 2a-e in very good yields. Semiempirical theoretical calculations (AMI) reveal two favoured conformations ( A and B ) for compounds 4a-e. The ¹H-nmr determinations, by using Karplus and Altona equations, clearly indicate that conformation A, with the aryl group on C5 in a pseudoaxial position, is that predominant in solution. The calculated charge density values for the olefinic carbons are in agreement with the experimental push-pull effect observed in the ¹³C-nmr spectra.     

Fluorescence properties of 2-aryl substituted indoles

The fluorescence properties of 2-phenylindole, 2-naphthylindole and 2-anthracenylindole were investigated. 2-Anthracenylindole was newly synthesized by Suzuki-Miyaura's coupling. The fluorescence quantum yield of 2-phenylindole was the highest and the fluorescence emission maximum wavelength of 2-anthracenylindole was the longest. The ab initio quantum chemical calculation of the 2-anthracenylindole showed that the HOMO and LUMO of 2-anthracenylindole were localized in the anthracene moiety.     

Synthesis and photophysical studies of novel 4-aryl substituted 2-phenyl-, 2-(fluoren-2-yl)- and 2-cymantrenylquinazolines

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Synthesis of functionally substitutedα,β-unsaturated epoxides

Conclusions A study was made of the condensation of 2,3-epoxybutyraldehyde, 2,3-epoxysuccinaldehyde mono-[dimethyl acetal], and ethyl 2,3-epoxysuccinaldehydate at their aldehyde groups with ethyl (triphenylphosphoranylidene)acetate, phosphonoacetic acid triethyl ester, (triphenylphosphoranylidene)acetone, (triphenylphosphoranylidene)aeetonitrile, and diethyl (cyanomethyl)phosphonate. The last two reactions lead to the formation of a mixture of cis and trans isomers.This article is published in accordance with a resolution of the Conference of Editors-in-Chief of Journals of the Academy of Sciences of the USSR of July 12, 1962, as a dissertation paper by B. I. Kozyrkin.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 683–688, April, 1966     

5-芳基-1,3,4-噻二唑-2-胺衍生物的合成

在冰醋酸催化下,芳香醛(2a～2g)分别和氨基硫脲(3)反应合成得到芳亚胺基硫脲衍生物(4a～4g),中间体4无需经柱层析纯化,然后在三氯化铁作用下反应关环,得到7个目标化合物5-芳基-1,3,4-噻二唑-2-胺(1a～1g).产物结构经1 H NMR、13 C NMR和ESI-MS确证.然后分别以中间体(E)-2-苄...     

Synthesis and structure of new substituted 2-dicyanomethylene-1,2-dihydropyridines

The synthesis of substituted 2-dicyanomethylene-1,2-dihydropyridines 3b-c and 2-dicyanomethylene-2,3,4,5-tetrahydropyridine 4 is accomplished from malononitrile dimer and propenenitriles 2 . All structures were determined by nmr techniques; however to put our structural assignment for 6-amino-3-cyano-5-ethoxycarbonyl-2-dicyanomethylene-1,2-dihydropyridine 3d on a firm and unequivocal basis we decided to perform X-ray diffraction analysis of this compound.     

Synthesis and theoretical calculations of novel 5-aryl substituted 2,4,7-trioxo and 4,7-dioxo-2-thioxopyrido[2,3-d]pyrimidines

New substituted pyrido[2,3-d]pyrimidines 5 and 6 have been prepared in one-step from the readily available 6-amino-2,4-dioxotetrahydropyrimidine ( 1 ) or 6-amino-4-oxo-2-thioxotetrahydropyrimidine ( 2 ) and the arylidene substituted Meldrum's acid. The substitution pattern of the ethylene moiety in compounds 5 and 6 results in a strong push-pull electronic effect. The semiempirical calculations using the AM1 method reveal two equally favoured conformations showing a distorted geometry. The calculated charge density values confirm the observed ¹³C nmr chemical shifts.     

Synthesis of stereodefined 1-aryl(heteroaryl) substituted 1,2-bis(2-bromopyridin-3-yl)ethenes by selective tandem Suzuki-Miyaura cross-coupling reactions

A protocol for the synthesis of stereodefined 1-aryl(heteroaryl) substituted 1,2-bis(2-bromopyridin-3-yl)ethenes by tandem Suzuki-Miyaura cross-coupling reactions and an example of convention into 5-phenyl-1,10-phenanthroline are described.     

Synthesis of novel C-2 substituted pyrimidine nucleoside analogs

A series of 2-(2-oxoalkylidene)-4(1H)-pyrimidinone nucleoside analogs were synthesized by the addition of the lithium enolates of methylketones to 2,5′- and 2,2′-anhydrouridines and to 2,5′-anhydrothymidines. Alternatively, 2-thiouridine was alkylated with bromomethyl ketones to yield 2-(2-oxoalkyl)thio-4(1H)-pyrimidinone ribofuranosides in good yields. These intermediates were subsequently transformed into the title compounds via an Eschenmoser sulfur extrusion reaction. The 2-(2-oxoalkylidene)-4-(1H)-pyrimidinone nucleoside analogs exhibit enol proton signals in their ¹H nmr spectra indicative of hydrogen bonding between N-3 and keto oxygen. These structures offer functional groups with potential for Watson-Crick hydrogen bonding.     

Synthesis and fluorescent properties of novel chiral 1,2-diaminocyclohexane substituted ligands and their complexes

A series of novel chiral 1,2-diaminocyclohexane derivatives bearing heterocyclic units were synthesized via improved methods under ultrasonic irradiation. The photophysical properties of compounds were studied in ethanol, methanol, and chloroform. The sensitivity of these amines toward Cu²⁺, Cd²⁺, and Ni²⁺ was studied by the UV–vis and fluorescent methods. The π-electron structure of thiophene and bithiophene containing sensors is the most active toward all above mentioned metal ions and is highly selective for Ni²⁺ and Cd²⁺.     

Synthesis of novel substituted spirohydantoins

The synthesis of novel N-1-alkylspirohydantoins (1-alkyl-1,3,8-triazaspiro[4.5]decanes) is reported. The key hydantoin intermediates 3 were prepared using standard hydantoin methodology. This synthesis allows for differential substitution of all three nitrogens.     

Synthesis of novel substituted flavonoids

Eighteen substituted chalcones, flavones and 3‐flavonols were synthesized and characterized using ¹H‐NMR, IR and elemental analysis. The substitution pattern includes two halogen atoms, nitro and methyl groups in ring A as well as two or three methoxy groups in ring B.     

Crystallographic analysis of a pair of isolable atropisomers of 2-aryl substituted indoline derivatives

The crystal and molecular structures of isomeric compounds of 1-(4′-chlorobenzoyl)-2-(2″-hydroxynaphthyl)-3,3-Dimethylindoline have been determined by single crystal X-ray analyses as a pair of diastereomeric atropisomers due to restricted rotation about a Csp³-Csp² bond.     

Synthesis and reactions of a stable 1,2-diaryl-1,2-dibromodisilene: a precursor for substituted disilenes and a 1,2-diaryldisilyne

Synthesis and isolation of the stable diaryldibromodisilene, Bbt(Br)SiSi(Br)Bbt, has been accomplished for the first time. The dibromodisilene underwent substitution reactions with organometallic reagents on the low-coordinated silicon atom to afford the corresponding substituted disilenes. Furthermore, the reaction of 1 with t-BuLi afforded the corresponding 1,2-diaryldisilyne, BbtSi[triple bond]SiBbt, the characters of which were revealed by spectroscopic and crystallographic analyses.     

Synthesis and properties of functionally substituted 1,2-azolidines

Results of investigations on the synthesis and properties of functionally substituted 1,2-azolidines are reviewed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 829–850, June, 1992.     

Synthesis of 4-aryl substituted 3,4-dihydropyrimidinones using silica-chloride under solvent free conditions

This paper describes an improved procedure for the efficient and facile synthesis of 4-aryl substituted 3, 4-dihydropyrimidinones under mild reaction conditions with excellent yields using inexpensive silica chloride under solvent free conditions.