Convenient Asymmetric Borane Reduction of Ketones Catalyzed by Simple Amino Alcohols and Corresponding Amino Acids

An asymmetric borane reduction of prochiral ketones catalyzed by simple amino alcohols and corresponding amino acids was examined to give alcohols with e.e. value up to 92% .

Enantiomeric Separation of Amino Alcohols by Ion-pair Chromatography

Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions enantiomeric propanolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3 v/v) as mobile phase on Lichrospher-100-DIOL column.

Synthesis,Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone

Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate （1S,3R）-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.

Synthesis and Immunosuppressive Activity of New Amino Alcohols Derivatives(II)

A series of new amino alcohols derivatives was synthesized with 6-bromo-2-tetralone as starting material, 6-substituted-2-tetralone as intermediate and Ullmann reaction, Suzuki reaction and spiro-hydantoin hydrolysis as key steps. The structures of key intermediate and target compounds were confirmed by 1H NMR, 13C NMR, IR and MS. Bioactivity researches show that the target compounds have certain inhibition effects on mice peripheral blood lymphocytes.

Enantioselective Reduction of Achiral Ketones with NaBH_4/I_2 Catalyzed by (S)-Ferrocenyl Amino Alcohols

The reduction reagents prepared from sodium borohydride, I-2 and a catalytic amount of chiral ferrocenyl amino alcohols 2a-e have been successfully applied to the enantioselective reduction of ketones. The optically active secondary alcohols were obtained in moderate enantiomeric excess and high chemical yield.

New strategies for asymmetric photocatalysis: asymmetric organocatalytic/photoredox relay catalysis for efficient synthesis of polycyclic compounds containing vicinal amino alcohols

An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.

A Novel Dimeric BINOL for Enantioselective Recognition of 1,2-Amino Alcohols

A novel auxillary chiral dimeric binol has been designed,synthesized,and used to enantioselectively recognize 1,2-amino alcohols through the three point of interactions,the reversible imine bond,resonance assisted hydrogen bonding and the hydrogen bonding by the additional chiral moiety introduced at the receptor.The enantioselectivities were comparable to those of the previous reported receptors.

Accurate Mass Determination of Amino Alcohols by Turboionspray/Time-of-Flight Mass Spectrometry

Amino alcohols were studied by turboionspray/time-of-flight mass spectrometry(TIS/TOF-MS) with the aim of determining the accurate mass of their protonated molecule ions.Polyethylene glycol (PEG) was used as the internal reference. Compared with the theoretical values,all relative errors were less than 5 x 10^(-6). The effects of nozzle potential, nozzle temperature,acquisition rate etc. on accurate mass determination were also studied.

Pinacol coupling going in a photocatalytic asymmetric manner:construction of chiral vicinal amino alcohols

Vicinal amino alcohols are a class of important motifs in pharmaceuticals,natural products as well as wide application in asymmetric catalysis（Scheme 1（a））.It is no doubt that development of efficient methods to access them has been a prominent research topic in the past decades.

Catalytic Enantioselective Reduction of Prochiral Ketones with Chiral Ferrocenyl Amino Alcohols

The asymmetric reduction of prochiral ketones was catalyzed by a class of recoverable and highly stable chiral ferrocenyl amino alcohols derived from natural amino acids to yield optically active secondary alcohols in high chemical yields and moderate to good enantiomeric excesses.

Enantioselective Addition of Phenylacetylene to Ketones Catalyzed by Chiral Amino Alcohols

（S）-（1-Benzylpyrrolidin-2-yl）diphenylmethanol and cinchonine were evaluated as promotors in the asymmetric additions of phenylacetylene to ketones, in order to prepare chiral propargylic alcohols. Good yields （up to 89%） and moderate enantioselectivities （up to 77.9% ee） were achieved. Addition of Ti（OPr-i）4 can significantly improve the enantioselectivity of the reaction.

Synthesis and Immunosuppressive Activity of New Amino Alcohol Derivatives(Ⅰ)

A series of new amino alcohol derivatives was synthesized and evaluated for their immunosuppressive activity on mouse peripheral blood lymphocytes.The structures were confirmed by means of 1H NMR,13C NMR,IR and MS.Most of the compounds display moderate to potent inhibitory activity.Compound 9d shows the most activity among them that are expected as a powerful candidate for safer immunosuppressant for organ transplantations and the treatment of autoimmune diseases.

Schiff-base Amino Alcohol-zinc Complex for Enantioselective Addition of Phenylacetylene to Aromatic Ketones

A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino acids in three steps. When the amount of ligand was 1%（molar fraction）, an e.e. value up to 94% was obtained. A series of practical chiral ligands were applied in the enantioselective addition of phenylacetylene to ketones without adding another stronger Lewis acid except zinc.

Simple and Mild Syntheses of Optically Active 2-(N,N-Dialkylamino)oxazolines

Chloroamidinium salts and a-amino alcohols derived from commercially available tetraalkyl ureas and α-amino acids, respectively, can be used for the syntheses of optically active 2-（N,N-dialkylamino）oxazolines in moderate to excellent yields without any catalyst. It is a simple and mild method for the syntheses of optically active oxazolines

Effect of topiramate on partial excitatory amino acids in hippocampal dentate gyrus of rats after alcohol withdrawal

BACKGROUND： Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE： To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN ： A randomized control animal experiment SETTING ： Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS： Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS： The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups： control group （n=10）, alcohol group （n=10） and topiramate-treated group （n=10）. Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol （10 mL/kg）, once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy （HPLC） respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES ： ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS： Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group （10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01）. In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol （6.06±0.82, 3.50±0.92, P 〈 0.05）, and the withdrawal scores at 48 and 72 hours were close to those in the control group （4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05）.② Changes of the contents of glutamic acid in hippocampal dentate gyrus： In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [（143.32±11.42）%, （99.12±0.69）%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [（78.50±16.40）%, （99.12±0.69）%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [（100.30±0.37）%, （118.91±10.40）%, （99.55±12.81）%, （99.08±11.42）%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group （P 〈 0.05）, and those at 30 and 72 hours were close （P 〉 0.05）. ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus： In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [（126.60±8.67）%, （129.17±10.40）%, （99.25±0.87）%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [（89.87±9.93）%, （99.25±0.87）%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [（100.27±0.32）%, （120.81 ±12.63）%, （98.91±7.83）%, （85.92±8.07）%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group （P 〈 0.05）, and those at 30 and 72 hours were close （P 〉 0.05）. CONCLUSION： ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats.

NiCo/Al_(2)O_(3)nanocatalysts for the synthesis of 5-amino-1-pentanol and 1,5-pentanediol from biomass-derived 2-hydroxytetrahydropyran

Al_(2)O_(3)-supported monometallic Ni,Co,and bimetallic Ni-Co nanocatalysts originated from layered double hydroxide precursors were synthesized by co-precipitation method,and used for the synthesis of useful 5-amino-1-pentanol(5-AP)and 1,5-pentanediol(1,5-PD)by reductive amination(RA)or direct hydrogenation of biofurfuralderived 2-hydroxytetrahydropyran(2-HTHP),respectively.In both reactions,the yield of the target products decreased monotonously with the increasing amounts of Co in the NiCo/Al_(2)O_(3)catalysts,owing probably to the replacement of highly reactive Ni by Co component with inferior hydrogenation activity at the low reaction temperature of 60℃.However,the incorporation of Co could improve the reducibility of the NiCo/Al_(2)O_(3)bimetallic catalysts and promote the reaction stability of the catalysts,especially for Ni_(2)Co1/Al_(2)O_(3),in both reactions with over 180 h time-on-stream.Characterization of the catalysts before and after the reaction showed that the incorporating Co could inhibit the sintering of metal particles and hinder the surface oxidation of the more reactive Ni0species,thanks to the formation of Ni-Co alloy in the bimetallic catalysts.DFT-based modeling of the reaction mechanisms is also performed,supporting the reaction pathway proposed previously and also the much higher activity of Ni in the RA of 2-HTHP as compared with Co.

Synthesis and Crystal Structure of N-(1'-Phenyl-2'-hydroxyethyl)-2,3-naphthylenedicarboximide

N (1 Phenyl 2 hydroxyethyl) 2,3 naphthylenedicarboximide(1a) was obtained by the reaction of 2,3 naphthylenedicarbonitrile with R phenylglycinol. 2,3 Naphthylenedicarboxylic acid, when reacts with thionyl chloride, gives 2,3 naphthalenedicarboxylic acid cyclic anhydride rather than the corresponding 2,3 naphthalenedicarboxylic acid dichloride. The former, when reacts with S leucinol, gives corresponding dicarboximide(1b). The crystal structure of compound 1a was determined by an X ray single crystal diffraction analysis. Compound 1a: C 40 H 30 N 2O 6, F W=634 66, orthorhombic, space group P 2(1)2(1)2(1), a =1 15556(5) nm, b =3 16552(12) nm, c =0 85984(3) nm; α= 90°, β=90°, γ=90°, V =3 1452(11) nm 3, Z=4, \{F(000)=\}1328, D c=1 340 g/cm 3, μ =0 091 mm -1 . Reflections collected/unique, 28053/4068( R int =0 0411); Final R indices : R 1=0 0337, wR 2=0 0687; Largest diff. peak and hole, 248 and \{-222\} e·nm -3 .

Synthesis and Crystal Structure of (2S,2'S,4'R)-2-(1-Hydroxy-1-ethylpropyl)-1-[(1'-p-tosyl-4'-hydroxypyrrolidin-2'-yl)methyl]pyrrolidine

The title compound （2S,2＇S,4＇R）-2-（1-hydroxy-1-ethylpropyl）-1-[（1＇-p-tosyl-4＇- hydroxypyrolidin-2＇-yl）methyl]pyrrolidine synthesized by using （2S,4R）-4-hydroxy-L-proline and L-proline as the main materials was characterized through IR, ^1H NMR, ^13C NMR and HRMS spectra as well as single-crystal X-ray diffraction analysis. There is one equivalent ethanol involved in the crystal （C23H40N2O5S, Mr = 456.63）. The crystal belongs to the triclinic system, space group P1, a = 6.5628（13）, b = 8.4228（17）, c = 11.957（2）°A, α= 80.54（3）,β= 83.19（3）, γ= 89.89（3）°, V= 647.3（2） °A^3, Z = 1, D, = 1.171 g/cm^3, λ（MoKα） = 0.71073°A,β = 0.158 mm^-1, F（000） = 248, the final R = 0.0465 and wR = 0.1336 for 1769 observed reflections with I〉 2σ（I）. The adjacent molecules of compound 5 are linked through intermolecular hydrogen bonds formed by the secondary hydroxy group of one molecule with the tertiary hydroxy group of another one, and the molecular chains are further linked by ethanol through two kinds of hydrogen bonds with two molecules from different chains respectively to form a supramolecular structure.

2-Amino homopropargyl alcohols from the highly regioselective Ag_2CO_3-catalyzed nucleophilic openings of alkynyl epoxides by amines

The nucleophilic ring opening reaction of propargyl epoxides by amines based on a silver catalyst is presented, The reaction takes place under mild conditions and features a high regioselectivity to provide an effective method for the synthesis of 2-amino homopropargyl alcohols in moderate to high yields,