New Approach to the Synthesis of 1,3-Chloroisothiocyanatoalkanes. Synthesis of Tetrahydro-1,3-thiazine-2-thiones and 2-Alkylamino-5,6-dihydro-1,3-thiazines

A method was developed to prepare 1,3-chloroisothiocyanatoalkanes by reducing 1,3-isothiocyanato ketones using sodium borohydride at pH ~7 and subsequent treatment of the resultant 1,3-isothiocyanato alcohols with thionyl chloride. The reaction of 1,3-chloroisothiocyanatoalkanes with sodium hydrosulfide or amines gives substituted tetrahydro-1,3-thiazine-2-thiones or 2-amino-5,6-dihydro-1,3-thiazines.     

Synthesis of Some Potential Antiangiogenic 1,3-Dihydro-1,3-dioxo-2H-isoindole Derivatives

The proliferation, invasion and metastasis of malignant tumors are closely related withangiogenesis induced by tumor cells. Blocking tumor-induced angiogenesis is anefficient strategy to prevent and cure cancer1. Recent studies indicated that theangiogenic process depends on vascular endothelial cell migration and invasion, whichregulated by αvβ3 receptor2. The receptor and extracellular matrix can recognize eachother through Arg-Gly-Asp (RGD) consensus sequence found in matrix ligands…     

5-氨基-1,3-二氢-1,3-二氧-异吲哚-2-丙酸类衍生物的合成及抗血管生成活性研究

根据RGD序列肽的构效关系, 设计并合成了一系列以5-氨基-1,3-二氢-1,3-二氧-异吲哚-2-丙酸为分子骨架的新化合物. 其中间体和目标物的化学结构经¹H NMR, MS和元素分析确证. 体外初步生物活性筛选结果表明, 目标物在10^－5 mol/L浓度下对bFGF诱导的鸡胚绒毛尿囊膜新生血管生成有显著抑制活性.     

1,3-二氢-1,3-二氧-2H-异吲哚类衍生物的合成及抗新生血管生成活性研究

根据整合素α_vβ₃受体内源性配基RGD三肽构效关系和作用机制,以沙利度胺为先导化合物,设计并合成了5个未见文献报道的5-羧基-1,3-二氢-1,3-二氧-2H-异吲哚类衍生物,其结构经元素分析、红外光谱及核磁共振谱确证.体外初步生物活性筛选实验结果表明,部分目标物对脐静脉血管内皮细胞株(ECV304)增殖有显著抑制活性.     

Electrochemical reduction of 5-halo-5-nitro-1,3-dioxanes and 2-halo-2-nitro-1,3-propanediols

The character of the first stage of reduction of 5-X-5-nitro-1,3-dioxanes 1—10 and 2-X-2-nitro-1,3-propanediols 11 and 12 is independent of the nature of halogen (X = Br, Cl) and substituents in position 2 of the dioxane cycle. The transfer of two electrons to a molecule of compound 1—12 is accompanied by the anionoid elimination of halogen and formation of the anion of nitronic acid. The high mobility of halogen is mainly due to the acceptor nitro group capable of further transformations in the -position to halogen. The direction of further reduction involving the electron transfer to electrochemically active groups in the aromatic fragment of the molecule is determined by the nature of these groups. Chloro-, bromo-, and iodophenyl-substituted derivatives 4, 5, and 8—10 are reduced as typical halobenzenes. In the case of nitrophenyl-substituted compounds 3 and 7, the dioxane cycle opens to form dianions of p- and m-nitrobenzaldehydes along with the reduction of the nitroso group through the stages of formation of the radical anion and radical anion of the nitroso group. The radical anions of the nitro and nitroso derivatives were identified by ESR.     

Zum Mechanismus der Reduktion von 1,3-Benzodithiol-2-thionen

Carbophilic reaction of 1,3-benzodithiole-2-thione (1) with trideuteroborane · dimethylsulfide, synthesized from NaBD₄ and BF₃ ·Me ₂S inTHF, gave 2,2-dideutero-1,3-benzodithiole (5 b) as well as the minor side-products7 b,8 and9 b.

     

Synthesis of 2-boryl-1,3-butadienes from tributylphosphine stabilized zirconacyclopropenes and alkynes

Boryl zirconacycopropenes stabilized with tributylphosphine react with alkynes (terminal and internal) to give predominately 2-boryl-1,3-butadienes, 5, in 40-81% isolated yields. Products 5 are accompanied by 4-boryl-1,3-butadienes in 7-23% when terminal alkynes are inserted. However, the use of an internal alkyne (3-hexyne) gave predominantly 6c.     

Cationic polymerizations of substituted 2-methylene-1,3-dioxocyclic acetals, 2-methylene-1,3-dithiolane and copolymerization of 2-methylene-1,3-dithiolane with 4-(t-butyl)-2-methylene-1,3-dioxolane1

Carbon black-supported sulfuric acid or BF₃·Et₂O-initiated polymerizations of 2-methylene-4,4,5,5-tetramethyl-1,3-dioxolane (1), 2-methylene-4-phenyl-1,3-dioxolane (2), and 2-methylene-4-isopropyl-5,5-dimethyl-1,3-dioxane (3) were performed. 1,2-Vinyl addition homopolymers of 1–3 were produced using carbon black-supported H₂SO₄ initiation at temperatures from 0°C to 60°C whereas both ring-opened and 1,2-vinyl structural units were present in the polymers using BF₃·Et₂O as an initiator. Cationic polymerizations of 2-methylene-1,3-dithiolane (4) and copolymerization of 4 with 2-methylene-4-(t-butyl)-1,3-dioxolane (5) were initiated with either carbon black-sulfuric acid or BF₃·Et₂O. Insoluble 1,2-vinyl addition homopolymers of 4 were obtained upon initiation with the supported acid or BF₃·Et₂O. A soluble copolymer of 2-methylene-1,3-dithiolane (4) and 4-(t-butyl)-2-methylene-1,3-dioxolane (5) was obtained upon BF₃·Et₂O initiation. This copolymer is composed of three structural units: a ring-opened dithioester unit, a 1,2-vinyl-polymerized 1,3-dithiolane unit, and a 1,2-vinyl polymerized 4-(t-butyl)-1,3-dioxolane unit. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2823–2840, 1999     

31P-NMR-SPEKTROSKOPISCHER NACHWEIS VON SUPERMESITYL-SUBSTITUIERTEM TRIPHOSPHAALLYLLITHIUM UND 2-ARSA-1,3-DIPHOSPHAALLYLLITHIUM

Abstract

The compounds 1.3-bis(2,4,6-tri-tert.butylphenyl)triphosphaallyllithium (5) and 1.3-bis(2,4,6-tritert.butylphenyl)-2-arsa-1,3-diphosphaallyllithium (7) are prepared by deprotonation of a phosphino-substituted diphosphene and arsaphosphene, resp. The presence of trans/trans and cis/trans isomers has been proven by ³¹P-NMR spectroscopy.

Die Verbindungen 1.3-Bis(2,4,6-tri-tert.butylphenyl)triphosphaallyllithium (5) und 1.3-Bis-(2,4,6-tri-tert.butylphenyl)-2-arsa-1,3-diphosphaallyllithium (7) werden durch Deprotonierung eines phosphino-substituierten Diphosphens bzw. Arsaphosphens dargestellt. Das Vorliegen von trans/trans und cis/trans-Isomeren wird durch ³¹P-NMR-Spektroskopie nachgewiesen.     

3(1,3-Heterazolidin-3-yl-methyl)-1,3-oxazolidines and their reduction with borane–THF

Preparation of bis-heterazolidines bonded by a CH₂, CH₂–S–CH₂ or CH₂SCH₂SCH₂ groups through their nitrogen atoms is reported: 3-(1,3-oxazolidin-3-ylmethyl)-1,3-oxazolidine 1, 3-(4,4-dimethyl-1,3-oxazolidin-3-ylmethyl)-1,3-oxazolidine 2, 3-(1,3-diazolidin-3-ylmethyl)-1,3-diazolidine 3, 3-(1,3-thiazolidin-3-ylmethyl)-1,3-thiazolidine 4, 3-(1,3-thiazolidin-3-ylmethylsulfanylmethyl)-1,3-thiazolidine 5 and 3-(1,3-oxazolidin-3-ylmethylsulfanylmethyl-sulfanylmethyl)-1,3-oxazolidine 6. The solid state structures of 4 and 5 were determined by X-ray diffraction analyses. BH₃–THF reduction reactions of compounds 1–6 were investigated. N→BH₃ mono- and di-adducts of 1–6 were prepared and their structures calculated (ab initio 3-21G*).     

Silylen-Reaktionen mit Selenophen und einem Tellurophen: Bildung und Strukturen eines 1,3-Diselena-2,4-disiletans und eines 1,3-Ditellura-2,4-disiletans [1]

Silylene Reactions with Selenophene and a Tellurophene: Formation and Structures of a 1,3-Diselena-2,4-disiletane and a 1,3-Ditellura-2,4-disiletane [1] Di-tert-butylsilylene, generated by photolysis of hexa-tert-butylcyclotrisilane, reacts with selenophene or 2,5-dimethyltellurophene by chalcogen abstraction to furnish the 1,3-diselena-2,4-disiletane 6 and 1,3-ditellura-2,4-disiletane 7 ring systems. The X-ray structure analyses of 6 and 7 reveal strictly planar four-membered rings with the smaller endocyclic angles at the chalcogen and the larger angles at the silicon atoms.     

Cationic ring‐opening polymerization of novel 1,3‐dehydroadamantanes with various alkyl substituents: Synthesis of thermally stable poly(1,3‐adamantane)s

Cationic ring‐opening polymerizations of 5‐alkyl‐ or 5,7‐dialkyl‐1,3‐dehydroadamantanes, such as 5‐hexyl‐ ( 4 ), 5‐octyl‐ ( 5 ), 5‐butyl‐7‐isobutyl‐ ( 6 ), 5‐ethyl‐7‐hexyl‐ ( 7 ), and 5‐butyl‐7‐hexyl‐1,3‐dehydroadamantane ( 8 ), were carried out with super Brønsted acids, such as trifluoromethanesulfonic acid or trifluoromethanesulfonimide in CH₂Cl₂ or n‐heptane. The ring‐opening polymerizations of inverted carbon–carbon bonds in 4–8 proceeded to afford corresponding poly(1,3‐adamantane)s in good to quantitative yields. Poly( 4–8 )s possessing alkyl substituents were soluble in 1,2‐dichlorobenzene, although a nonsubstituted poly(1,3‐adamantane) was not soluble in any organic solvent. In particular, poly( 8 ) exhibited the highest molecular weight at around 7500 g mol^?1 and showed excellent solubility in common organic solvents, such as THF, CHCl₃, benzene, and hexane. The resulting poly( 4–8 )s containing adamantane‐1,3‐diyl linkages showed good thermal stability, and 10% weight loss temperatures (T₁₀) were observed over 400 °C. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4111–4124     

Synthesis and photochromic properties of 1,2-dihetarylethenes with 1,3-dioxole- and 1,3-oxazole-2-thione bridges

Methods for the synthesis of substituted bis(2,5-dimethyl-3-thienyl)ethenes with 1,3-dioxole- and 1,3-oxazole-2-thione fragments as ethene bridges were developed. These compounds exhibit photochromic properties. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1299–1301, May, 2005.     

Reactions of 1,3-dioxacycloalkanes and their 2-arsena, 2-bora, 2-germa, 2-sila,and 2-thia analogs with nitriles

New reactions of five-, six-, and seven-membered 1,3-dioxacycloalkanes and their 2-arsena, 2-bora, 2-germa, 2-sila, and 2-thia analogs with nitriles giving rise to 1,3-oxazacycloalkanes and then to amino alcohols are surveyed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1499–1507, July, 2005.     

1,3-Dipolar cycloaddition of phthalazinium ylides to 5-arylidene-2-spirocyclohexane-1,3-dioxane-4,6-diones

Tetrahydrospiropyrrolo[2,1-a]phthalazines were synthesized by the reaction of 5-arylidene-2-spirocyclohexane-1,3-dioxane-4,6-diones with phthalazinium ylides. One of the reaction products, viz., 3-ethoxycarbonyl-2-(4-methoxyphenyl)-2′,2′-pentamethylene-1,2,3,10b-tetrahydrospiro[pyrrolo[2,1-a]phthalazine-1,5′-[1,3]dioxane]-4′,6′-dione, was studied by X-ray diffraction. The spectroscopic characteristics of the reaction products are discussed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2362–2365, October, 2005.     

Synthesis of 2-substituted benzo-1,3-ditelluroles

A method for the synthesis of 2-phenylbenzo-1,3-ditellurole by the reaction of disodiumo-benzeneditellurolate with benzylidene chloride was proposed. 2-Methylbenzo-1,3-ditellurole and benzo-1,3-ditellurole-2-carboxylic acid were prepared by the reaction of 2-lithiobenzo-1,3-ditellurole with MeI and CO₂, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1132–1134, June, 2000.     

Synthesis and stereochemistry of new 1,3-thiazolidine systems based on 2-amino-2-(mercaptomethyl)propane-1,3-diol: 4,4-bis(hydroxymethyl)-1,3-thiazolidines and c-5-hydroxymethyl-3-oxa-7-thia-r-1-azabicyclo[3.3.0]octanes

The thiaminalisation of 2-amino-2-(mercaptomethyl)propane-1,3-diol [‘2-(hydroxymethyl)cysteinol’] with aryl(di)aldehydes is reported. The resulting new class of 2-aryl-4,4-bis(hydroxymethyl)-1,3-thiazolidines is investigated by NMR and IR spectroscopy in tandem with DFT calculations, permitting structural assignments that are discussed in terms of conformational analysis, anomeric effects and ring-chain tautomerism. These acquired data are subsequently exploited. After treatment with formaldehyde, the subsequent (double) regio- and diastereoselective oxaminalisation of the 1,3-thiazolidine building-block affords the first non-symmetric series of a thiazolidin-oxazolidine fused system singly functionalised at the C-5 position. An unexpected rearrangement, which consists of the partial relocation of the Ar ligand from the 1,3-thiazolidine to the 1,3-oxazolidine ring, is observed as a major influence on the substitution of the Ar ring. The first single crystal X-ray analysis of the title bicyclic system, which discloses the homo- and/or heterochiral non-bonding interactions, is also presented.     

Synthesis of some new 3-[5-(2-oxo-2H-3-chromenyl)-1,3-oxazol-2-yl]-1,3-thiazolan-4-ones as antimicrobials

<正>A series of some new 2-imino-5-[(Z)-1-(4-methylphenyl)methylidene]-3-[5-(2-oxo-2H-3-chromenyl)-1,3-oxazol-2-yl]-1,3- thiazolan-4-ones 5a-j has been synthesized and assayed for their antibacterial activity against Gram-positive bacteria viz.Bacillus subtilis(ATCC 6633),Staphylococcus aureus(ATCC 6538p) and Micrococcus luteus(IFC 12708),and Gram-negative bacteria viz. Proteus vulgaris(ATCC 3851).Salmonella typhimurium(ATCC 14028) and Escherichia coli(ATCC 25922).Among the screened compounds,5d,5e,5f,5g,and 5j exhibited potent inhibitory activity compared to standard drug,and emerged as potential molecules for further development.     

One-pot synthesis of new 2,4,5-trisubstituted 1,3-thiazoles and 1,3-selenazoles

In this work, we describe the synthesis of new 2,4,5-trisubstituted-1,3-thiazoles and 1,3-selenazole achieved by an easy one-pot four-step procedure. Expected compounds were obtained in good yield from dimethyl cyanodithioimidocarbonate, which was the common starting material for the preparation of all 1,3-thiazoles and 1,3-selenazoles. Chemical diversity was introduced on thiazole and selenazole rings by varying the amines and the activated halides used.     

Electron ionization and methane chemical ionization mass spectrometry study of some 2,2-disubstituted 1,3-dioxolanes, 1,3-dithiolanes, 1,3-oxathiolanes and 1,3-dioxanes. Gas-phase lactone and thiolactone formation

The electron ionization and methane chemical ionization mass spectra of some 2,2-disubstituted 1,3-dioxolanes, 1,3-dithiolanes and 1,3-oxathiolanes were studied. Especially, the effect of the length of the side chain in ring position 2 of these compounds and the ease of formation of possible lactone/thiolactone ion as a fragmentation product were examined. In addition, two 2,2-disubstituted 1,3-dioxanes were studied to see the effect of the bigger ring size. The formation of lactone ions was more favorable under methane chemical ionization than under electron ionization conditions. The structures of fragment ions and the ions generated from model compounds were carefully studied using both high- and low-energy collision-induced dissociation. Also ab initio molecular orbital calculations up to the HF/6–31G** level of theory for protonated 2-methyl-2-propanoic acid ethyl ester of 1,3-dioxolane, 1,3-oxathiolane and 1,3-dithiolane and for two isomeric bicyclic ions were carried out. The theoretical results obtained favor the formation of the lactone ion. Copyright © 2005 John Wiley & Sons, Ltd.