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.     

Preparation of chiral C2-symmetrical 1,1′-disubstituted ferrocenes

A biocatalytic procedure for the resolution and concurrent desymmetrization of tetraacetoxyferrocene (±, meso)-2 is described. Enantiomerically pure (R,R)- and (S,S)-forms have been converted into the corresponding epoxide 6, a useful starting material for the preparation of polyfunctional C₂-symmetric ferrocenes.     

Synthesis of Optically Active Aromatic Ether Ketone Macrocycles Containing 2,2′-Dimethoxy-1,1′-binaphthyl-6,6′-diyl Moieties

Optically active aromatic ether ketone macrocycles containing 2,2′-dimethoxy-1,1′-binaphthyl-6,6′-diyl moieties were synthesized through electrophilic aromatic substitution reaction and stepwise nucleophilic aromatic substitution reactions. Structures of the resulting macrocycles were confirmed by NMR and matrix assisted laser desorption/ionization time of flight (MALDI-TOF) mass measurements.     

Crystal structure of 1,1′-biphenyl-2,2′,3,3′-tetracarboxylic and 1,1′-biphenyl-2,2′,3,3′,5,5′,6,6′-octacarboxylic acids: solid-state chiralization and dissociation

X-ray diffraction analysis revealed unexpected stereochemical features accompanying crystal self-assembly of the two title oligocarboxylic acids.     

Synthesis of Novel Polycyclic Carbamate Derivatives of 2-Hydroxy-2,2′-biindane-1,1′,3,3′-tetrone

Russian Journal of Organic Chemistry - Methyl 1,3,11′-trioxo-1,3,10a′,11′-tetrahydro-4β′H-spiro[inden-2,10′-indeno[1,2-b]chromene]-7′(8′)-ylcarbamates...     

Crystal structure of three solvates of 1,1′-binaphthyl-2,2′-bicarboxylic acid with 2-picoline

From solutions in 2-picoline (2-methylpyridine), depending on the temperature of crystallization, the universal clathratogen — 1,1′-binaphthyl-2,2′-bicarboxylic acid (BBA) — precipitates as crystals of three types with different composition and structure. Under normal conditions (room temperature), the precipitate is crystals of BBA disolvate with 2-picoline; a temperature reduction of 20°C results in the crystallization of monosolvate dihydrate; and a temperature increase of the same level results in the precipitation of monosolvate. That is, as the temperature of crystallization rises, the number of included guest molecules gradually decreases and the space where they are located becomes more closed. In 1:1:2 BBA/2-picoline/H₂O solvate (space group P2₁/n, a = 11.991(2) Å, b = 9.317(2) Å, c = 22.283(5) Å, β = 99.77(3)○, V = 2453.3(9) ų, Z = 4), the carboxyl groups of the BBA molecule at the C21 atom are deprotonated and the released proton goes to the nitrogen atom of 2-picoline. BBA molecules interact with those of 2-picoline and water via H bonds to form infinite chains in direction [111], which, in their turn, join together into infinite two-dimensional sheets parallel to plane (?101). 2-Picoline molecules are located in the channels. In BBA/2-picoline disolvate (space group C ₂/c, a = 11.7523(11) Å, b = 13.8563(13) Å, c = 17.9615(13) Å, β = 108.044(9)○, V = 2781.1(4) ų, Z = 4), one BBA molecule and two H bond 2-picoline molecules form a 0-dimensional associate of the type G-H-G. The solvent molecules are also located in the channels. In BBA/2-picoline monosolvate (space group P2₁/c, a = 9.299(5) Å, b = 12.727(5) Å, c = 19.011(5) Å, β = 95.248(5)○, V = 2240.5(16) ų, Z = 4), each BBA molecule is H-bonded with a 2-picoline molecule to form a 0-dimensional associate of the type H-G. Guest molecules are located in closed cavities.     

Microwave Accelerated Synthesis of 2,2′,3,3′-Biphenyltetracarboxylic Dianhydride

Polyimides have been widely used in aerospace and microelectronics due to their excellent mechanical properties and thermo oxidative stability[1].However,most of aromatic polyimides are severe difficult to process because of their bad solubility in common solvents and intractable in their fully imidized forms,which restrict their applications and developments[2,3].     

Synthesis of poly(2,2′,3,3′-indole)

New approaches to the synthesis of poly(2,2′,3,3′-indole) were developed based on the photochemical dehydropolycondensation of indole in the presence of iodine and the photochemical polycondensation of 1-(1H-indol-3-yl)-2-iodo-1-ethanone in the absence of catalyst and solvent. A suggested mechanism for the formation of the oligomeric chain in these reactions includes the intermediate formation of 3,3′-diindole with subsequent polycondensation via elimination of hydrogen atoms at position 2 of the dimer pyrrole fragment.     

Synthesis of chiral N,N′-disubstituted 1,2-benzenediamines from o-dibromobenzene

Palladium-catalyzed amination of o-dibromobenzene provided chiral N,N′-disubstituted 1,2-benzenediamines in good to excellent yields. The amination was executed stepwise and in one pot to give unsymmetrically and symmetrically substituted 1,2-benzenediamines. Incorporation of chiral primary amines was possible without racemization using catalytic Pd₂dba₃–BINAP.     

Synthesis of 1,1′-Dibenzo- and 1,1′-Dinaphtho-2,2′-Dithiols from the Respective Thiophenes

The title compounds 1 and 2 were prepared from the respective, inexpensive and readily available thiophenes via reaction with lithium and sulfur monochloride, followed by reduction with lithium aluminium hydride.     

Developments in the Dehydrogenative Electrochemical Synthesis of 3,3′,5,5′-Tetramethyl-2,2′-biphenol

The symmetric biphenol 3,3′,5,5′-tetramethyl-2,2′-biphenol is a well-known ligand building block and is used in transition-metal catalysis. In the literature, there are several synthetic routes for the preparation of this exceptional molecule. Herein, the focus is on the sustainable electrochemical synthesis of 3,3′,5,5′-tetramethyl-2,2′-biphenol. A brief overview of the developmental history of this inconspicuous molecule, which is of great interest for technical applications, but has many challenges for its synthesis, is provided. The electro-organic method is a powerful, sustainable, and efficient alternative to conventional synthesis to obtain this symmetric biphenol up to the kilogram scale. Another section of this article is devoted to different process management strategies in batch-type and flow electrolysis and their respective advantages.     

Ferroelectric liquid crystals with axially chiral 2,2′-spirobiindan-1,1′-dione cores

The axially chiral mesogens 5-alkoxy-5′-[(4-alkoxybenzoyl)oxy]-2,2′-spirobiindan-1,1′-dione (QL7-n) were synthesised as racemic mixtures and resolved as single enantiomers by preparative chiral phase HPLC. The shorter homologues (R)-QL7-8 and QL7-9 form enantiotropic N* and SmC* phases, whereas the longer homologues (R)-QL7-10 and QL7-12 form an enantiotropic SmC* phase only. Texture analysis showed that the helical pitch of the N* phase is below the wavelength range of visible light; a helical pitch of 187 nm was measured at T – T_NI = –5 K by selective reflection using enantiomerically enriched mixtures of (R)- and (S)-QL7-8 (0.35 ≤ ee ≤ 0.80). Spontaneous polarisations were measured as a function of temperature in the SmC* phase by the triangular wave method. P_S values at saturation range from 102 nC cm^–2 for (R)-QL7-8 to 120 nC cm^?2 for (R)-QL7-9, which are up to three times greater than the highest polarisation previously reported for an axially chiral SmC* mesogen. Optical tilt angles θ were measured as a function of temperature and showed a sharp rise consistent with first-order N*–SmC* or I–SmC* transitions, with values at saturation ranging from 42 to 44°.     

Asymmetric Synthesis and Characterization of Chiral 2,2′‐Diamino‐3,3′‐diethoxycarbonyl‐8,8′‐diphenyl‐1,1′‐biazulene

Abstract

rac‐2,2′‐Diamino‐3,3′‐diethoxycarbonyl‐8,8′‐diphenyl‐1,1′‐biazulene was synthesized from diethyl 2‐aminoazulene‐1,3‐dicarboxylate and was optically resolved into two enantiomers of S‐form and R‐form. The enantioselective oxidative couplings with two chiral amines [(?)‐sparteine and (R)‐(+)‐α‐methylbenzylamine] and ferric chloride catalyst, and the asymmetric couplings with two chiral oxovanadium(IV) complexes of ethyl 2‐amino‐4‐phenylazulene‐1‐carboxylate, easily yielded chiral 2,2′‐diamino‐3,3′‐diethoxycarbonyl‐8,8′‐diphenyl‐1,1′‐biazulene. Therefore, the introduction of two phenyl groups at the 8‐ and 8′‐postions of each azulene ring using phenyl magnesium bromide via an addition–oxidation–decarboxylation mechanism resulted in 1,1′‐biazulene forming a chiral C₂ axis.     

Synthesis and application of novel chiral phosphino-oxazoline ligands with 1,1′-binaphthyl skeleton

C₁-Symmetric phosphino-oxazolines, (S,S)- and (S,R)-2-[4-(isopropyl)oxazol-2-yl]-2′-diphenylphosphino-1,1′-binaphthyl, which possess both phosphine and oxazoline moieties, were prepared from racemic binaphthol and enantiomerically pure (S)-(+)-2-amino-3-methyl-1-butanol in high yields. Reaction of 1,3-diphenyl-2-propenyl acetate with dimethyl sodiomalonate in the presence of 2 mol% of palladium catalysts bearing the new chiral ligands proceeded with high enantioselectivity to give allylic alkylation products of up to 91% ee.     

6,6′-Dibromo-3,3′-dimethoxy-2,2′-dihydroxy-1,1′-biphenyl: preparation and resolution

A pratical route to prepare the title biphenyl 1 starting from 3,3′,2,2′-tetramethoxy-1,1′-biphenyl 2 is described. Resolution of 1 was achieved by its conversion into the corresponding diastereomeric menthyldicarbonate. The absolute configuration of (P)-(+)-1 was confirmed by X-ray analysis of the related diastereomer.     

A Practical Procedure for the Solid-Phase Synthesis of Racemic 2,2′-Dihydroxy-1,1′-binaphthyl

Abstract: A high yielding solid-phase dimerisation of 2-naphthol by means of a ball-milling procedure is described.

     

Synthesis,characterization and properties of 3,3′-diethyl-1,1′-oxydiethylenedicarbonyl bis(thiourea)

In this paper, 3,3′-diethyl-1,1′-oxydiethylenedicarbonyl bis(thiourea) (DEOECTU), was synthesized by phase transfer catalysis and then characterized by UV, elemental analysis, infrared spectra, mass spectrum, ¹H NMR and TGA. DEOECTU properties, such as response to metal ions, adsorption on sulfide mineral surfaces, and hydrometallurgical performance as flotation collectors, were also investigated. The results indicated that DEOECTU reacted chemically with Cu²⁺ ions through its S and N atoms in the C(=S)–NH–C(=O) group to form a new chelate compound, but no reaction of DEOECTU with Zn²⁺, Pb²⁺, Fe³⁺ or Fe²⁺ ions was observed. The results of adsorption and flotation experiments demonstrated, that compared to pyrite, sphalerite and galena, DEOECTU exhibited a superior collecting power for chalcopyrite and might attach on chalcopyrite surface by chemisorption. The further theoretical analysis from Pearson’s HSAB view point briefly explained the experimental results of the selective response of DEOECTU to Cu²⁺ ions and chalcopyrite.     

Synthesis of Schiff bases by aromatic amine condensation with 3,3′-bithiophenes-2,2′ and 4,4′-dicarbaldehydes

Reactions of aromatic amines with 3,3′-bithiophene-2,2′-dicarbaldehyde 1 and 3,3′-bithiophene-4,4′-dicarbaldehyde 2 gave the 2,2′-(N-(aryl)diimino)-3,3′-bithiophene 3 and 4,4′-(N-(aryl)diimino)-3,3′-bithiophene 4 in good yields. Orthophenylenediamine reacted with 1 and 2 to give dithieno[3,4-c;4′,3′-e]azepino[1,2-a]benzimidazole 5 and dithieno[2,3-c;3′,2′-e]azepino[1,2-a]benzimidazole 6. All these original products have been characterized by spectroscopic techniques and elemental analysis.     

The Synthesis of Dialdehyde from Sodium Hydrogen Telluride with 1,1′,3,3′—Tetramethyl—2,2′—bis—benzimidazolium Salt

The reaction of bis-benzimidazolium salts with sodium hydrogen telluride is reported,and a new synthetic method for dialdehydes is provided.     

Studies of electronic structures of 1,1′-disubstituted silaoxacyclohexa-3,5-dienes

Spatial and electronic structures of 1,1-disubstituted silaoxacyclohexa-3,5-dienes have been calculated using the AMPAC and HYPERCHEM 3.0 program packages. Interatomic distances, bond angles, torsion angles, atomic charges, electron densities, bond orders, parameters of localized molecular Orbitals,etc. have been determined. Based on data obtained, it has been concluded that the -R'SiO-fragment in these molecules is a saturated structural linkage, which exhibits an inductive effect on the diene system; however, the linkage does not interact with the diene system by the mesomeric (resonance) mechanism.Translated fromIzvestiya Akademii Nauk. Setiya Khimicheskaya, No. 10, pp. 1917–1920, October, 1995.