Conjugate additions of Me2CuLi to enantiopure gamma-hydroxy-delta-sulfinyl and sulfonyl pentenoates

[reaction: see text] A systematic study of dimethyl cuprate conjugate additions to diastereoisomeric ethyl gamma-hydroxy (or tert-butyldimethylsilyloxy)-delta-p-tolylsulfinyl-2-pentenoates and the analoguous sulfones showed mainly 3,4-anti diastereoselectivity when the reaction occurred in the presence of TMSCl. The pi-facial diastereoselection is mainly governed by the gamma-hydroxy or silyloxy group, whereas the role of the sulfur functionality is to increase the reactivity of the pentenoate system, probably by assisting the transfer of the alkyl group from the cuprate. This was evidenced by the reactions on similar systems that lack the sulfur functions. The appropriate choice of NH4OH or HCl hydrolysis in the workup allowed direct access to the open chain products or the lactones.     

Chloro- and iodotrimethylsilane-activated additions of organocopper compounds to enones and enoates

Organocopper compounds add to enones and enoates in the presence of chlorotrimethylsilane in ether giving the conjugate adducts in preparatively useful yields via the silyl enol ethers. Presence of lithium iodide is important and excess of chlorotrimethylsilane accelerates the reactions.The combination of organocopper compound, iodotrimethyl-silane and dimethyl sulfide gave faster reactions and very high yields, particularly in dichloromethane, where the reaction mixtures gradually became homogeneous.     

Enantioselective conjugate additions of organolithiums to BHA enoates mediated by A chiral ligand

The conjugate addition reactions of BHA alkenoates with organolithiums in toluene or toluene-hexane at −78 °C were mediated by the chiral ligands 1 and 2 to give the corresponding 3-substituted alkanoates in high ees and high yields. The two ligands are complementary each other, 1 is effective for phenyl- and vinyllithiums to give the adducts in 64–93% ee, while 2 is effective for butyl- and ethyllithiums to give the adducts in 91–99% ee.     

Asymmetric synthesis of β-substituted alcanoic acids via highly stereoselective conjugate additions of organocopper compounds to chiral enoates

Conjugate additions of organocopper compounds RCu·.BF₃ to encates of sulfonamide-shielded alcohols 1x and 1n quite generally proceed with > 99% ee and > 90% yield.     

Synthesis of 8-arylsulfoxyl/sulfonyl adenines

We report a method for the synthesis of 9-N-alkyl-8-arylsulfoxyl adenines and 9-N-alkyl-8-arylsulfonyl adenines. The approach starts with a tandem one-pot reaction that by using Mitsunobu conditions converts 8-arylsulfanyl adenines to the corresponding iminophosphorane protected 9-N-alkyl-8-arylsulfanyl adenines. These compounds were further subjected to selective OXONE^®/alumina mediated oxidation followed by deprotection of the amine leading to the desired sulfoxides and sulfones.     

氟芳胺基、氟磺酰胺基磷酸酯的合成

首次合成了氟芳胺基磷酸酯和氟磺酰胺基磷酸酯.对氟苯胺、α-氯-4-三氟甲基吡啶胺、α-氯-4-三氟甲基氧化吡啶胺与二乙氧基磷酰氯在乙腈或DMF中反应,得到氟芳胺基磷酸酯.氟烷基磺酰甲胺与二乙氧基磷酰氯反应,以金属钠处理,相应钠盐在乙腈或DMF中,于室温下反应将得到氟烷磺酰胺基磷酸酯.     

Synthesis of multi-hydroxyl and sulfonyl dual-functionalized room temperature ionic liquids

Starting from the hydroxylamine (dimethyl amino ethanol, triethanolamine) and 1,3-propane sultone, a series of hydroxyl and sulfonyl dual-functionalized zwitterionic salts and corresponding acidic room temperature ionic liquids have been synthesized. The hydroxyl groups of the synthesized substances were confirmed by the 1H NMR measurement. These zwitterionic salts and ionic liquids may be used for synthesizing other functionalized ionic liquids or ionic liquid-polymer (polyelectrolyte).     

Synthesis of sulfonyl and sulfenyl derivatives of pyridine and 1,2,4-triazole

The corresponding sulfonamides and sulfenamides were synthesized from 5-methyl-4-phenyl-4H-1,2,4-triazole-3-thiol and 6-tert-butyl-3-cyano-4-phenylpyridine-2-thiol.     

NMR studies on the reaction between methacrylonitrile and trimethylaluminum

The reaction of MAN with AlMe₃ was studied by the ¹³C- and ¹H-NMR spectral measurement. In the presence of an excess of AlMe₃, it was found that a 1:1 complex of MAN and AlMe₃ is initially formed and subsequently dimethyl(α-methyl isopropylidene amino)aluminum is produced by the reaction of the complex with AlMe₃. The isolated product was pale yellow crystal (mp 39–40°C). The kinetics of the reaction were also examined.     

Synthesis of (sulfonyl)methylphosphonate analogs of prenyl diphosphates

Syntheses of several (sulfonyl)methylphosphonate analogs of geranyl, neryl, and farnesyl diphosphates are described. Key steps include utilization of an (E)-selective Horner-Wadsworth-Emmons olefination which couples an aldehyde to the sulfone phosphonate moiety, and a selective reduction of the resulting dienyl sulfone phosphonate substrates.     

Synthesis of some novel sulfonyl ester derivatives derived from d-mannitol

The preparation of sulfonate-derivatives of d-mannitol i.e. 1,2:3,4-di-O-isopropylidene-3,4-di-O-p-toluenesulfonate-d-mannitol (3a), 1,2:3,4-di-O-isopropylidene-3,4-di-O-methanesulfonate-d-mannitol (3b), and 1, 2:3,4-di-O-isopropylidene-3,4-di-O-trifluoromethanesulfonate-d-mannitol (3c) is described. Full characterization and methodologies of these sulfonate-d-mannitol derivatives have been described as well.     

Importance of trimethylaluminum diffusion in three-step ABC molecular layer deposition using trimethylaluminum, ethanolamine, and maleic anhydride

Hybrid organic-inorganic films were grown by molecular layer deposition (MLD) with a three-step ABC reaction sequence using (A) trimethylaluminum (TMA), (B) ethanolamine (EA), and (C) maleic anhydride (MA) at 90 °C. Very large steady state mass gains of 1854-4220 ng/(cm(2) cycle) were measured depending on reaction conditions. These mass gains are much larger than typical mass gains for surface reactions. The quartz crystal microbalance (QCM) mass profiles during the TMA reaction were consistent with TMA diffusion into and out of the ABC films. The ABC mass gains per cycle also displayed a strong dependence on the TMA dose and purge times that was consistent with the effects of TMA diffusion. Multiple dose experiments conducted at 130 °C revealed that the ABC reactions were self-limiting for thin ABC films. For thicker ABC films, increased TMA diffusion into the ABC film led to non-self-limiting behavior. Numerical modeling assuming Fickian diffusion for TMA diffusing into and out of the ABC film could fit the QCM mass profiles. The results all indicate that TMA diffusion into the ABC MLD film plays a key role in the thin film growth. In addition, X-ray reflectivity (XRR) measurements revealed that the ABC films were exceptionally smooth.     

Magnesium-induced regiospecific C-silylation of suitably substituted enoates and dienoates

The β-aryl-β-silyl and β,β-disilyl propionates have been synthesized from cinnamates and β-silyl acrylates by a regiospecific reductive C-silylation using Mg/silyl chloride/DMF system at room temperature. These reductive C-silylation conditions have also been applied to δ-aryl substituted dienoates wherein silylation took place at the δ-position leading to the synthesis of single regioisomeric allylsilanes with very high stereoselectivity.     

Isolation of the complex between acrylonitrile and trimethylaluminum

The complex of acrylonitrile (AN) with trimethylaluminum (AlMe₃) was successfully isolated as a white needlelike crystal with a melting point of 42.5°C. In this article the preparation of the complex is described in detail. Cryoscopic and spectral investigations indicated that the complex is formed by an equimolar ratio of AN and AlMe₃. From the measurement of the x-ray diffraction photograph of the crystal the repeat period was determined to be 9.47 ± 0.05 Å.     

Ion-molecule reactions in mixtures of trimethylaluminum and methylamines

The ion-molecule reactions of mixtures of trimethylaluminum and methylamines, to serve as a model system for group 13–15 semiconductor fabrication, were examined by using Fourier transform ion cyclotron resonance mass spectrometry. Sequential ion-molecule reactions leading to formation of multiple adduets were observed for each of the reactant mixtures investigated. Collision-induced dissociation was used to probe the adduct structures. There is evidence for hydrogen bonding between the amines and aluminum in most of the adducts studied. Rearrangement of the aluminum/nitrogen skeletons was not observed, although the aluminum/nitrogen bonds appear to be relatively strong, so that stable adducts can be formed. The monomethylamine and dimethylamine readily produce gas-phase neutral adducts with trimethylaluminum, which can be related to the basicities of the methylamines.     

Synthesis and physical characterization of electrically conducting polymers of polynuclear aromatic sulfonyl compounds

Potentially useful conducting polymers of sulfonyl substituted phenanthrene derivatives and non-conducting linear polymers, such as, polystyrene and poly(N-vinylcarbazole) have been synthesized and characterized using IR, thermogravimetric and dielectric measurements. The phenanthrene-based benzene, naphthalene and biphenyl copolysulfones have also been prepared and characterized through these techniques. These pendant and backbone polymer sulfones have exceptionally high thermal stability and electrical conductivity, such that dc conductivity in the range 2.80 × 10^?16 to 2.82 × 10^?7 Ω^?1 cm^?1 and ac conductivity in the range 1.69 × 10^?7 to 2.10 × 10^?6 Ω^?1 cm^?1.     

1-Aminothiaalkanephosphonic acids and their sulfinyl and sulfonyl derivatives: Synthesis and acidic properties

Several 1-aminothialkanephosphonic acids 2 were synthesized and selectively oxidized to their sulfinyl 3 and sulfonyl 4 derivatives. For the compounds 2 , 3 , and 4 , their dissociation properties were determined potentiometrically.     

Selective formation of 1,5-substituted sulfonyl triazoles using acetylides and sulfonyl azides

The reaction of acetylides with sulfonyl azides was found to selectively form 1,5-substituted sulfonyl triazoles. This reaction thus provides access to the regioisomeric product as compared to the popular copper-catalyzed azide-alkyne cycloaddition. The reaction is efficient and selective with a variety of alkyne sources and sulfonyl azides and can incorporate an additional electrophile to yield 1,4,5-trisubstituted sulfonyl triazoles.     

Synthesis and characterization of a novel electrolyte based on bis[(perfluoroalkyl)sulfonyl]triimide trianion

The facile preparation and characterization on a novel trisodium salt based on bis[(perfluoroalkyl)sulfonyl]triimide trianion were reported for the first time. High oxidation potential was observed for the new salt in organic solvent. Ionic conductivities of this new salt and other monomeric sodium salts were determined in different organic solvents over a temperature range between 10 and 100 °C.