A C2-Symmetric Chiral 2,2′-Bipyridine Derived from Tartaric Acid

The synthesis of the C₂-symmetric, homochiral bipyridine 1, whose atropisomeric stereochemistry is imposed by a side-chain derived from tartaric acid, is reported.     

C2-Symmetric sulfur derivatives of 2,2′,3,3′-tetramethoxybiphenyl

A practical route to prepare dithioether, thiophene and thiophene S-dioxide derivatives of 2,2′,3,3′-tetramethoxy-1,1′-biphenyl 1 is described. Resolution of 6,6′-bis(methylthio)-3,3′-dimethoxy-[1,1′-biphenyl]-2,2′-diol 15 was achieved and its absolute configuration was assigned by X-ray analysis of the corresponding phosphorothioamidate diastereomer 18.     

Synthesis of New Dioxacyclophanes Derived from 1,1′-Binaphthyl-2, 2′-diol

Abstract

The Williamson reaction between (R,S)-[1,1′-binaphthyl]-2, 2′-diol 1 and (R,S)-2,2′-bis (bromomethyl)-1,1′ binaphthyl 2 in acetone, gave the diastereoisomeric dioxacyclophanes (R?, S?)-3a and (R?, R?)-3b in high yield.     

Highly Stereoselective Synthesis of β-D-ribofuranosyl Phosphopnates

１－Ｏ－三氟乙酰基－２，３，５－三－Ｏ－苯甲酰基－β－Ｄ－核糖在ＢＦ３·Ｅｔ２Ｏ催化下可与磷酸二酯发生反应，并且高收率、高立体选择性地得到一类新的磷酸核糖酯类化合物。其产物结构为单一的β－构型。     

Synthesis and Luminescence Spectral Properties of New Cyano-Substituted 2,2′-Bipyridine Derivatives

Russian Journal of Organic Chemistry - Previously unknown 2-{4-aryl-5-cyano-[2,2′-bipyridin]-6(1H)-ylidene}malononitriles were synthe­sized by reaction of...     

Stereoselective Synthesis of α-Aminonitril on Glucose Templates

Both proteinogenic and non proteinogenic α-amino acids are of particular interest as constituents of peptide factors, peptidomimetics and antibiotics for the construction of modern selective drugs. [1] Furthemore, α-amino acid derivatives are interesting building units for chiral-pool syntheses of enantiomerically pure natural products. [2] Numerous efforts in modern organic synthesis are centered on the synthesis of enantiomerically pure α-amino acids. [3] During the past three decades efficient methods of asymmetric synthesis of α-amino acids have been developed; most of them are based on electrophilic transformations of organometallic intermediates. [4] Using the concept that the chirality of the carbohydrates can be exploited for diastereoselective reactions, Kunz and his cooperator had developed a Strecker synthesis with glycosyl amines as chiral auxiliaries. [5]     

A Short and Highly Stereoselective Synthesis of Cerebrosterol

Ｃｅｒｅｂｒｏｓｔｅｒｏｌ (2 4Ｓ ｈｙｄｒｏｘｙｃｈｏｌｅｓｔｅｒｏｌ,1)ｆｏｒｍｅｄｉｎｓｍａｌｌａｍｏｕｎｔｓｉｎｈｕｍａｎａｎｄａｎｉｍａｌｂｒａｉｎ1ｆｒｏｍｃｈｏｌｅｓ ｔｅｒｏｌｉｓｉｍｐｏｒｔａｎｔｆｏｒｃｈｏｌｅｓｔｅｒｏｌｈｏｍｅｏｓｔａｓｉｓｉｎｔｈｉｓｏｒｇａｎ .Ｔｈｅｅｘｃｅｓｓｃｈｏｌｅｓｔｅｒｏｌｉｓｃｏｎｖｅｒｔｅｄｉｎｔｏ 2 4Ｓ ｈｙｄｒｏｘｙ ｃｈｏｌｅｓｔｅｒｏｌｂｙａｕｎｉｑｕｅｂｒａｉｎ ｓｐｅｃｉｆｉｃ 2 4Ｓ ｈｙｄｒｏｘｙｌａｓｅ ,ｗｈｉｃｈｃｏｕｌｄｂｅｒ…     

Synthesis of 1,1′-binaphthyl-2,2′-diamine from 2-naphthol under atmospheric pressure

A practical protocol to obtain 1,1'-binaphthyl-2,2'-diamine was developed from 2-naphthol and 2-naphthylhydrazine under mild conditions:solvent-free,125-130℃,atmospheric pressure.The convenient procedure makes the process amenable for large-scale synthesis of the versatile compound.     

Synthesis and some reactions of a 2,2′-biphospholyl

1,1′-Diphenyl-3,3′,4,4′-tetramethyl-2,2′,5,5′-tetrahydro-2,2′-biphosphole obtained by reductive dimerization of the appropriate phosphole has been converted into the corresponding 2,2′-biphosphole by P-bromination followed by dehydrobromination of the resulting P,P′-tetrabromo compound with α-picoline. This 2,2′-biphosphole gives two isomeric P-sulfides upon reaction with sulfur, and a Mo(CO)₄ chelate upon reaction with Mo(CO)₆. Cleavage of the two P-phenyl bonds by lithium in THF yields the corresponding biphospholyl anion, which is converted into a mixture of two isomeric bis(η⁵,η⁵-2,2′-diphosphafulvalene)diirons by treatment with FeCl₂. The reaction of Mn₂(CO)₁₀ in boiling xylene affords a mixture of three complexes, including a (η⁵,η⁵-2,2′-diphosphafulvalene)hexacarbonyldimanganese produced by thermal cleavage of the two PPh bonds. Under CO pressure there is a [1,5] P → C shift of the two phenyl groups, leading to formation of (η⁵,η⁵-3,3′-diphenyl-2,2′-diphosphafulvalene)hexacarbonyldimanganese.     

Concise Total Synthesis of (−)-Vermiculine through a Rhodium-Catalyzed C2-Symmetric Dimerization Strategy

A short and efficient synthesis of the C₂-symmetric antibiotic (−)-vermiculine by utilizing an enantioselective catalytic one-step dimerization methodology as key-step to construct the core structure is reported. The late-stage modifications feature a double metathesis homologation followed by a double Wacker-type oxidation. These key-steps allowed the synthesis of vermiculine in only seven steps, starting from commercially available building blocks.     

Synthesis, Crystal Structure and Properties of a Europium Complex with 3-Iodobenzoic Acid and 2,2′-Bipyridine

The complex [Eu(3-IBA)3·2,2'-bipy]2 was synthesized from 3-iodobenzoic acid (3-HIBA), 2,2'-bipyridine (2,2'-bipy) and EuCl3·6H2O by hydrothermal synthesis, and its crystal structure was determined by X-ray single-crystal diffraction. It is of triclinic, space group P, with a = 10.958(2), b = 12.311(3), c = 12.556(3) (A), α = 81.549(3), β = 82.404(4), γ = 78.348(3)°, Mr = 1049.15, V = 1631.7(6) (A)3, Z = 1, Dc = 2.135 g/cm3, F(000) = 980, λ(MoKα) = 0.71073 A, μ(MoKα) = 4.804 mm-1, the final R = 0.0329 and wR = 0.0723 for 4640 observed reflections with I ＞ 2σ(I). The Eu(Ⅲ) ion is eight-coordinated and two Eu(Ⅲ) ions are held together by four 3-iodobenzoate groups in the bidentate bridging mode. The complex was characterized by DTA-TG, IR, UV and fluorescence spectra.     

Synthesis and Characterization of Polymers Derived from the Copolymerization of 1,1′-Dihydroxyethyl-2,2′-Biimidazole and the Diglycidyl Ether of Bisphenol A

Abstract

1,1′-Dihydroxyethyl-2,2′-biimidazole has been used as a copolymerizing monomer with the diglycidyl ether of bisphenol A in the preparation of biimidazole-containing epoxy polymers. Polymerization reactions were studied in bulk, with and without catalyst, and in N,N-dimethylforma-mide and anisole solvents, with and without catalyst. FT-IR and NMR spectra, molecular weight, thermal and solubility characteristics were obtained. Polymers isolated as amorphous light brown solids were found to be only sparingly soluble in THF or in highly polar nitrogen-containing solvents (DMF, NMP, pyridine). These materials exhibited molecular weights up to 37 000 for SnC1₄-catalyzed polymerization carried out in DMF. A glass-transition temperature of 391°C was observed for polymers obtained under uncatalyzed solventless conditions. The glass transition temperature was 373°C for product obtained under SnC1₄-catalyzed, solventless conditions. Thermogravimetric analysis in air of polymers obtained under varying solvent and catalyst conditions showed less than 25% weight loss below 330°C and greater than 75% weight loss above 400°C.     

The Synthesis of a New Dumbbell-shaped Compound of Bis-4, 4′-bipyridine Bridged by 2, 2′-Bipyridine

The title compound 5 was synthesized in 45% yield by the reaction of compound 3 with α,α′-bis (bromomethyl)-2, 2′-bipyridine in CH3CN at 70℃ for 24 h.     

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc（II） Complex with 2,2′-Diphenic Acid and 2,2′-Bipyridine Ligands

A new dinuclear complex [Zn(dpa)(bipy)(H2O)]2 (dpa = 2,2'-diphenic acid, bipy = 2,2'-bipyridine) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 10.960(2), b = 9.4841(18), c = 20.599(4), β = 104.452(3)o, V = 2073.4(7)3, C48H36N4O10Zn2, Mr = 959.55, Dc = 1.537 g/cm3, μ(MoKα) = 1.225 mm-1, F(000) = 984, Z = 2, the final R = 0.0364 and wR = 0.0843 for 2788 observed reflections (I > 2σ(I)). In the crystal structure, the zinc atom is five-coordinated with two carboxylate oxygen atoms from different dpas, one coordinated water molecule and two nitrogen atoms from bipy ligands, showing a slightly distorted triangular bipyramidal geometry. Furthermore, it exhibits a zero-dimensional network structure with a sixteen-membered ring and shows yellow photoluminescent property at room temperature.     

Highly Stereoselective Synthesis of Phenylseleno- and p-Tolylsulfonyl Substituted 1,3-Dienes from Functionalized Allyl Alcohols

Introduction Heteroatom-substituted 1,3-dienes have been exten-sively studied because of their marked abilities to con-struct highly functionalized ring systems in cycloaddi-tions.1 For example, Danishefsky2 developed 1-methoxy-3-trimethyl-siloxy-buta-1,3-diene which has led to many creative applications in complex organic synthesis. Padwa et al.3 demonstrated that 1,3- and 2, 3-bis(phenyl-sulfonyl)-1,3-butadienes are versatile building blocks in organic synthesis via reactions such as [4+2]-c…     

Synthesis of a Diterpene 1,3,4-Oxadiazolin-2′-one from Dimethylcyclopentenonepimarate

A diterpene 1,3,4-oxadiazolin-2-one was synthesized by lead-tetraacetate oxidation of 16,17- epoxydimethylcyclpentenonepimarate. The structures of the synthesized compounds were confirmed by IR and NMR spectroscopies.     

Synthesis,Crystal Structure and Bioactivity of a Pd(Ⅱ) Complex with Demethylcantharate and 2,2′-Bipyridine

A novel crystal with the molecular formula [Pd(DCA)(bipy)]2 [Pd(bipy)Cl2 ]·6.75H2O was formed by PdCl2 with disodium demethylcantharate (Na2 (DCA),DCA2= 7-oxa-bicyclo[2.2.1]heptane-2,3-bicarboxylate) and 2,2-bipyidine (bipy) through the hydrothermal method.The complex was characterized by elemental analysis and infrared spectroscopy.The structure of the complex was determined by single-crystal X-ray diffraction,which is of triclinic system,space group P1 with a=13.6818(7),b=14.8426(8),c=15.0043(8),α=97.319(3),β=92.521(3),γ=105.776(2)°,V=2898.4(3) 3,Dc=1.545 g·cm-3,Z=1,F(000)=1420,S=0.852,the final R=0.0525 and wR=0.1777 for 13634 observer reflections (I>2σ(I)).The binding reaction of the complex with ct-DNA and bovine serum albumin (BSA) was studied by fluorescence spectroscopy.The results indicated that the complex binds to ct-DNA via the partial intercalation.The binding constant K A of the complex interaction with BSA was 3.98×10 5 L·mol-1 and one binding site would be formed.The antiproliferative activity of the complex against human hepatoma cells (SMMC7721) in vitro is much higher than that of Na 2 (DCA).     

A Convenient Synthesis of 3, 4′-Bipyridine

3, 4′-Bipyridine was synthesized from 6-methoxy-3, 4′-bipyridine or 6-benzyloxy-3, 4′-bipyridine via 6-chloro-3, 4′-bipyridine. The chloro derivative was catalytically dechlorinated into the corresponding 3, 4′ -bipyridine.     

Synthesis of Antipyrine Derivatives Derived from Dimedone

Coupling of dimedone with the diazonium salt of 4-aminoantipyrine afforded 2,3-dimethyl-4-[2-（5,5-dimethyl- 2,6-dioxocyclohex-2-ylidend）-hydrazino]-5-oxo-1-phenylpyrazoline （3）. Reaction of 3 with excess phenylhydrazine gave the mixed trishydrazone derivative 4. Treatment of 3 with hydroxylamine produced the bisoxime 5 which upon dehydrative cyclization with acetic anhydride gave the corrsponding tetrahydrobenzo[d][1,2,3]triazole derivative 7. A one-pot synthesis of 7 was done by reacting 3 with hydroxylamine hydrochloride in pyridine, followed by heatment with acetic anhydride.     

An Improved Synthesis of 2,2′-Dimercaptobiphenyl

The preparation of transition-metal thiolato complexes as synthetic biomimics¹ has led to a resurgent interest in the synthesis of organic thiols and their derivatives. The compound 2,2′-dimercaptobiphenyl, 1, offers interesting possibilities as a ligand, and it has been used recently to displace iron-sulfur clusters from low molecular-weight Fe-S proteins.² The two previous preparations for 1 require a coupling reaction of diazonium salts.^3,4 Overall yields of 10%³ and 30%⁴ are made even less attractive by the need to precipitate copper by-products with H₂S after the coupling step.