Search

A copper catalyzed enantioselective formal aza-Diels-Alder reaction of in situ formed 1,2-diaza-1,3-dienes from α-halohydrazones and vinyl diazo compounds was described. The protocol provides a variety of optically enriched diazo-containing tetrahydropyridazines in moderate yields and with up to excellent enantioselectivities. The present methodologies utilize chiral oxazolines as the chiral ligands for asymmetric catalysis and feature mild reaction conditions, readily available substrates, and broad substrate scope.

Catalytic asymmetric 1,2-allylation of aurone-derived azadienes is very difficult to achieve due to the driving force for aromatization and the greater steric hindrance of 1,2-addition compared with 1,4-addition. By taking advantage of the ability of nitrogen ligated metal complexes, we successfully demonstrated the first example of copper-catalyzed 1,2-allylation of azadienes with allylboronates for the highly enantioselective synthesis of homoallylic amines. Meanwhile, the enantioenriched 1,4-addition products could also be obtained through a subsequent 3,3-sigmatropic rearrangement of the 1,2-addition products. Extensive DFT calculations were carried out to elucidate the origins of high regioselectivity (1,2- vs 1,4-) and enantioselectivity.

The copper-catalyzed enantioselective allylation reaction of N -aryl aldimines has been developed using a combination of Cu(OAc) 2 and SPINOL-based phosphonamidite. This protocol significantly broadens the substrate scope, such that imines bearing various ortho -substituents on the N -aryl were converted smoothly into homoallylic amines in up to 99% yield and 98% ee. Taking advantage of the diversity of the N -aryl motif, three kinds of N -heterocyclic compounds were constructed, respectively, from the corresponding homoallylic amines in merely one step.

A nickel-catalyzed three-component alkylarylation of alkenyl N -heteroarenes with α-bromocarboxylates and aryl boronic acids is reported. The protocol provides a new method to access a variety of N -heteroarene substituted diarylalkanes in moderate to good yields. It features mild reaction conditions, cheap nickel catalyst, readily available substrates, and broad substrate scope.

A Lewis acid Sc(OTf) 3 -catalyzed annulation reaction of vinyl diazoacetates with in situ formed α,β-unsaturated imines for the preparation of indole-fused tricyclic rings has been reported. This strategy involves a sequential addition/rebound addition process of vinyl diazoacetates and an in situ dedinitrogenation. This annulation protocol features low-cost catalysts, mild reaction conditions, and facilely prepared substrates.

An unprecedented cycloaddition of vinyl diazo compounds with benzofuran-derived azadienes catalyzed by rarely independently used NaBAr F 4 has been established. Benzofuran-fused hydropyridines were constructed with excellent yields and high diastereoselectivity via a Na + -catalyzed inverse-electron-demand aza-Diels-Alder reaction. Notably, this transformation also features good compatibility with a one-pot protocol to deliver the spiro[benzofuran-cyclopentene] skeleton, as well as perfect atom economy and simple reaction conditions.

Herein, we report the Pd(0)-catalyzed intermolecular asymmetric dearomative [3 + 2] annulation of phenols with vinyl cyclopropanes via in situ generated ortho -quinone methide intermediates. A series of highly functionalized spiro-[5,6] bicycles which bear three contiguous stereogenic centers including one all-carbon quaternary were obtained with excellent stereoselectivities. Density functional theory (DFT) calculations indicate that the reactions were controlled by thermodynamics.

The intermolecular addition of allylic copper species generated from diene and copper hydride remains elusive. Herein copper hydride catalyzed asymmetric cross reductive coupling of conjugated dienes and ketoimines including trifluoromethyl ketoimines and α-iminoacetates was first achieved using chiral Ph-BPE as the ligand, providing rapid access to structurally and optically enriched homoallylic amines containing two vicinal stereogenic centers with up to 95% yield, 99% ee, and 11:1 diastereoselectivities.

The first catalytic enantioselective [3 + 2] cycloaddition reaction between vinylcyclopropanes and alkenyl N -heteroarenes in the presence of LiBr and a Pd(0)/SEGPHOS complex was developed. LiBr plays a key role in improving the reactivity of alkenyl N -heteroarenes as a mild Lewis acid.

Due to the limitations of the treatment process of urban sewage treatment plants and the complexity of water sources, the rich inorganic nitrogen and trace persistent organic matter in the reclaimed water cause potential human health risks through lateral leakage or bioaccumulation during the replenishment process of rivers and lakes. Exploring the distribution law of different types of reclaimed water characteristic water quality factors and their formation in reclaimed water replenishment river channels is of great significance to river and lake management. This study takes the Beijing-Tianjin-Hebei section of the North Canal as the research area and explores the spatial variation characteristics of conventional physical parameters, full index, inorganic nitrogen, and salinity hydronium antibiotics in river water quality with the help of clustering, discrimination, principal components, and variance decomposition. The results showed that, although the spatial distribution patterns of different types of water quality factors were consistent, they all showed significant mid-upstream and downstream distribution; however, there were big differences in the degree of variation and the mechanism of variation. The spatial variation of inorganic nitrogen and antibiotics was the most obvious, whereas the variation in conventional physical parameters and the full index was the weakest, and the salinity hydronium showed moderate variation. The spatial variation mechanism of conventional physical parameters was mainly reflected in microbial degradation. The full index was the result of the combined effect of microorganisms, diffusion, the synergy of the two, and a certain degree of source-sink homogeneity. Diffusion was the main mechanism affecting the spatial variation in salinity hydronium. The spatial variation mechanism of inorganic nitrogen was mainly reflected in the source-sink homogenization and microbial degradation; as a secondary mechanism of the spatial variation of inorganic nitrogen, diffusion had a synergistic mode with microbial degradation. Antibiotics, which have great differences in chemical structural stability and biodegradability, showed high spatial variability and had the highest diffusion and microbial synergy mechanism. This research provides a quantitative analysis of the spatial variability mechanism of water quality based on variance decomposition, which has practical guiding significance for the causes of the spatial variability of river pollutants and river management.

The first asymmetric synthesis of 3-methyleneindolines from alkynyl imines has been developed via a rhodium-catalyzed tandem process: regioselective alkynylation of the internal alkynes and subsequent intramolecular addition to the imines. The reaction proceeded with unconventional chemoselectivity and provided 3-methyleneindolines with good yields (up to 82% yield) and high enantioselectivities (up to 97% ee). Moreover, this transformation also features mild reaction conditions, perfect atom economy, and a broad substrate scope.

Background: Psoriasis is a chronic inflammatory skin disease, affecting about 0.6% of the Chinese population. Many patients are not well controlled by conventional treatments, thus there is need for new treatment regimens. In this study, we assessed the efficacy and safety of secukinumab in Chinese patients with moderate to severe plaque psoriasis., Methods: This study was a 52-week, multicentre, randomized, double-blind, placebo-controlled, parallel-group, Phase 3 trial. A sub-population of study participants (≥18 years) of Chinese ethnicity were randomized to receive subcutaneous injections of 300 or 150 mg secukinumab, or placebo. The co-primary endpoints were psoriasis area severity index (PASI) 75 and Investigator's Global Assessment (IGA) 0/1 at Week 12., Results: A total of 441 Chinese patients were enrolled in this study. Co-primary outcomes were achieved; 300 and 150 mg secukinumab were superior to placebo as shown in the proportion of patients that achieved PASI 75 (97.7% and 87.2% vs. 3.7%, respectively; P < 0.001), and IGA 0/1 (82.3% and 69.7% vs. 2.7%; P < 0.001) at Week 12. Treatment efficacy was maintained until Week 52. There was no increase in overall adverse events with secukinumab relative to placebo throughout the 52-week period., Conclusion: Secukinumab is highly effective and well tolerated in Chinese patients with moderate to severe plaque psoriasis., Trial Registration: ClinicalTrials.gov, NCT03066609; https://clinicaltrials.gov/ct2/show/record/NCT03066609.

Background: Benvitimod cream, a novel synthetic small molecule, was effective in treating mild-to-moderate plaque psoriasis. We conducted a phase III clinical trial to assess the efficacy and safety of benvitimod cream in patients with mild-to-moderate plaque psoriasis., Methods: We randomly assigned 686 patients (2:1:1) to receive 1% benvitimod cream, 0.005% calcipotriol ointment or placebo twice a day for 12 weeks. The primary efficacy end points were the percentage of patients with a 75% or greater reduction from baseline in the psoriasis area and severity index (PASI 75) score and with a score of 0 or 1 in static physician's global assessment (sPGA) at week 12., Results: The results showed that 50.4% of patients in the benvitimod group achieved PASI 75, which was significantly higher than that in the calcipotriol (38.5%, P < 0.05) and placebo (13.9%, P < 0.05) groups. The proportion of patients achieving an sPGA score 0 or 1 was 66.3% in the benvitimod group and 63.9% in the calcipotriol group, which were both significantly higher than that in the placebo group (34%, P < 0.05). In the long-term follow-up study, 50.8% of patients experienced recurrence. After retreatment with 1% benvitimod, 73.3% of patients achieved an sPGA score of 0 or 1 again at week 52. Adverse events included application site irritation, follicular papules, and contact dermatitis. No systemic adverse reactions were reported., Conclusion: During this 12-week study, benvitimod cream was demonstrated with high effectiveness and safety in patients with mild-to-moderate plaque psoriasis., Trial Registration: Chinese Clinical Trial Registry (ChiCTR), ChiCTR-TRC-13003259; http://www.chictr.org.cn/showprojen.aspx?proj=6300., (Copyright © 2020 The Chinese Medical Association, produced by Wolters Kluwer, Inc. under the CC-BY-NC-ND license.)

The 2019 novel coronavirus infection has brought a great challenge in prevention and control of the national epidemic of coronavirus disease 2019 (COVID-19) in China. During the fight against the epidemic of COVID-19, properly carrying out pre-examination and triage for patients with skin lesions and fever has been a practical problem encountered in hospitals for skin diseases as well as clinics of dermatology in general hospitals. Considering that certain skin diseases may have symptom of fever, and some of the carriers of 2019 novel coronavirus and patients with COVID-19 at their early stage may do not present any symptoms of COVID-19, to properly deal with the visitors to clinics of dermatology, the Chinese Society of Dermatology organized experts to formulate the principles and procedures for pre-examination and triage of visitors to clinics of dermatology during the epidemic of COVID-19., Competing Interests: Conflicts of interest: The authors reported no conflicts of interest., (Copyright © 2020 Hospital for Skin Diseases (Institute of Dermatology), Chinese Academy of Medical Sciences, and Chinese Medical Association, published by Wolters Kluwer, Inc.)

Asymmetric conjugate addition of PhMe2SiBPin to a wide range of N-heteroaryl alkenes proceeded in the presence of a copper catalyst coordinated with an easily accessible chiral phosphoramidite ligand to afford useful β-silyl N-heteroarenes in high yields (up to 96%) and excellent enantioselectivities (up to 97% ee).

The first copper hydride (CuH)-catalyzed asymmetric 1,6-conjugate reduction of p -quinone methides is reported. This protocol provides a new method to access a variety of triarylmethanes and 1,1,2-triarylethanes in good yields with excellent enantioselectivities and broad functional group tolerance.

Palladium-catalyzed asymmetric formal [3 + 2] cycloaddition of vinyl cyclopropanes and aldimines or isatin-derived ketimines proceeded smoothly in the presence of chiral phosphoramidite ligands. The corresponding highly functionalized and optically enriched pyrrolidine or spiro[pyrrolidin-3,2'-oxindole] derivatives are obtained in up to 94% yield and with up to 96% ee and 7:1 dr.

Basal cell carcinoma (BCC) is the most common type of human skin cancer, which is driven by the aberrant activation of Hedgehog signaling. Previous evidence indicated that sex determining region Y-box 2 (SOX2) is associated with the tumor metastasis. However, the expression and role of SOX2 in BCC remain unknown. Therefore, the aim of the current study was to analyze the possible mechanism of SOX2 in the progression of BCC. The levels of SOX2 in BCC cells were detected by reverse transcription-quantitative polymerase chain reaction. Transwell assays were also used to determine the migration and invasion of BCC cells. Immunoblotting and immunofluorescence were used for analyzing the role of SOX2 knockdown in the serine-arginine protein kinase 1 (SRPK1)-mediated phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway in BCC cells. The results demonstrated that SOX2 is overexpressed in BCC tissues and cells. In addition, SOX2 knockdown inhibited the migration and invasion of BCC cells, and the epithelial-mesenchymal transition (EMT) progress of BCC cells. It was also observed that SOX2 knockdown decreased SRPK1 expression, which further led to the downregulation of PI3K and AKT expression levels in BCC cells. Furthermore, SRPK1 transfection or PI3K/AKT pathway activation abolished the inhibitory effects of SOX2 knockdown on the migration, invasion and EMT progress of BCC cells. In conclusion, these results indicated that SOX2 may potentially serve as a target for BCC therapy by targeting the SRPK1-mediated PI3K/AKT signaling pathway.

A Cu(ii)/bisoxazoline ligand-promoted formal [4 + 1] cycloaddition of diazo esters with azoalkenes formed in situ has been developed. This strategy provides a potential protocol for the construction of dihydropyrazoles containing a quaternary center with good to excellent yields., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Rodium chiral diene complex-catalyzed enantioselective cycloaddition of aryl α-diazoarylacetates and electron-enriched Danishefsky-type dienes afforded highly functionalized and optically enriched cyclopentenones in excellent yields (up to 97% yield) and with good to excellent enantioselectivities (60-92% ee). (-)-1,13-Herbertenediol was successfully synthesized in an overall 25% yield employing the optically enriched cyclopentenone with an all-carbon quaternary center as the key intermediate.

Objective: To investigate the epidemic features of persistent genital chlamydial infection (GCI) in Tianjin area., Methods: We statistically analyzed the clinical data about the persistent GCI patients received at the Venereal Disease Clinic of Tianjin Medical University General Hospital from 2009 to 2011., Results: A total of 158 patients with persistent GCI were received from Tianjin area. The patients ranged in age from 19 to 67 years, 39.24% from 20 to 29 and 34.81% from 30 to 39 years, 36.71% with commercial occupation, and 55.06% with college education or above. The sex partners of the patients included their spouses (32.91%) and waitresses (41.77%). The incidence probability of persistent GCI was higher in the females (59.49%) than in the males. Many of the patients were complicated with infections of mycoplasma, syphilis, candida albicans, or condyloma acuminatum., Conclusions: The epidemic trend of persistent GCI is rather grim in Tianjin area. New measures have to be developed targeting the epidemiological features of persistent GCI for better prevention and control of the disease.

The researches on chlamydia in recent years show that chlamydia bacteriophage may be a potential and effective means to solve the clinical infection of chlamydia trachomatis (Ct). We investigated the biological effect of chlamydiaphage phiCPG1 capsid protein Vp1 on Ct both in McCoy cells and genital tract of mice. Different concentrations of Vp1 were co-incubated with Ct E serotype strain in McCoy cells. Female BALB/c mice were used to establish Ct E strain-induced urogenital infection model. They were randomly divided into five groups and given different treatments on the fifth day after Ct inoculation. Animals in groups 1 and 2 were given 30 μL different concentrations of Vp1 in the genital tract respectively, those in group 3 were intramuscularly injected with 30 μL Vp1, those in the infected group did not receive any intervention, and those in the control group received 30 μL PBS in the genital tract. The vaginal discharge was collected to identify the live chlamydia by cell culture and gene fragment by real time PCR different days after infection. Inhibition rate of 100 μg/mL and 50 μg/mL Vp1 proteins against Ct E strain in the McCoy cell cultures was 91% and 79% respectively. The number of intracellular Ct inclusion in the McCoy cells co-cultured with vaginal discharge of group 1 and group 2 was less than in the infected group, and that in group 1 was less than in group 2, on the 7th day after Ct inoculation. Real-time PCR showed that chlamydia concentration of the vaginal discharge in group 2 was lower than in the infected group, and that in group 1 was lower than in group 2 on the 10th day. It was suggested that Vp1 capsid proteins had inhibitory effect on the proliferation of Ct serovar E strain in cell culture and mouse genital tract.

Syphilis is a sexually transmitted disease caused by Treponema pallidum. Minocycline, a representative tetracycline derivative, has the greatest antimicrobial activity among all tetracyclines. There are few reports about treating syphilis with minocycline because there is a lack of efficacy data from controlled trials. We compared the rates of serological cure in patients with early syphilis who were treated with minocycline or benzathine penicillin G (BPG).During the study period, a total of 40 syphilis patients received the BPG treatment, which was a single intramuscular dose of 2.4 million units of BPG, and 156 patients were treated with minocycline; 77 patients were placed in the 2-week, standard minocycline therapy group and received 100 mg of minocycline orally, twice daily for 14 days, and 79 patients were placed in the 4-week, lengthened minocycline therapy group and received 100 mg of minocycline orally, twice daily for 28 days. The outcome of interest was the rate of serological cure in these patients.At the end of the 2-year follow-up, the serological cure rate of the 4-week, lengthened minocycline therapy group (87.34%) was higher than that of both the 2-week, standard minocycline therapy group (72.73%) and the BPG treatment group (77.50%). In addition, the curative effect of the 4-week, lengthened minocycline therapy was significantly greater than that of the 2-week, standard minocycline therapy in patients who were aged >40 years; exhibited an initial rapid plasma reagin titer ≥1: 32; or exhibited secondary syphilis (P = 0.000, 0.008, 0.000; <0.05).Minocycline appears to be an effective agent for treating early syphilis, especially when applied as a 4-week, lengthened therapy., Competing Interests: The authors have no conflicts of interest to disclose.

A new metal-free, ring-expansion reaction of six-membered N-sulfonylimines with unstable diazomethanes, generated in situ from the N-tosylhydrazones, has been developed. This reaction delivers valuable seven-membered enesulfonamides by a Tiffeneau-Demjanov rearrangement and intramolecular proton transfer tautomerization process. Moreover, this ring-expansion reaction can be carried out in a one-pot fashion and scaled up to the gram scale by using aryl aldehydes, without the need to isolate the N-tosylhydrazone., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The aim of the present study was to determine the in vitro susceptibility of wild-type and mutant clinical isolates of Chlamydia (C.) trachomatis strains to erythromycin, azithromycin and josamycin, and to identify the resistance-conferring 23S ribosomal (r)RNA mutations in the isolates. The wild-type resistant isolates were defined as those with minimum inhibitory concentration values above the tissue concentration of the antibiotic in the urogenital system. Furthermore, all resistant C. trachomatis isolates were exposed to sub-inhibitory concentrations of macrolides, and 13 resistant mutants were selected following serial passages. Among the 8 wild-type isolates that were resistant to erythromycin, 3 isolates had a mutation at T2611C in the 23S rRNA gene while the others did not show any 23S rRNA mutations. The selected mutant isolates showed a 4- to 16-fold reduction in in vitro sensitivities. With regard to the mutant strains, the T2611C mutation was found in 10 isolates, A2057G mutation in 6 isolates, and A2059G mutation in 1 isolate. Thus, the macrolide-resistant isolates of the wild-type strain had different mutations from those selected by exposure to sub-inhibitory concentrations of macrolides. Also, since 23S rRNA mutations were not identified in certain isolates, it was considered that other molecular mechanisms may also be responsible for the macrolide resistance of C. trachomatis .

Enantioselective formal hetero-Diels-Alder reactions of trifluoromethylated enones and 2-amino-1,3-butadienes generated in situ from aliphatic acyclic enones and chiral primary amines are reported. The corresponding tetrahydropyran-4-ones are formed in up to 94 % yield and with up to 94 % ee. The reaction was carried out through a stepwise mechanism, including initial aminocatalytic aldol condensation of 2-amino-1,3-butadiene to the trifluoromethylated carbonyl group followed by an intramolecular oxa-Michael addition. Both NMR investigation and theoretical calculations on the transition state indicate that the protonated tertiary amine could effectively activate the carbonyl group of the trifluoromethyl ketone to promote the addition process through hydrogen-bonding interaction of N-H⋅⋅⋅F and N-H⋅⋅⋅O simultaneously, and thus provide a chiral environment for the approach of amino-1,3-butadienes to the activated trifluoromethyl ketone, resulting in high enantioselectivity., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A palladium-catalyzed (3 + 2) cycloaddition of vinyl cyclopropane and α,β-unsaturated imines generated in situ from aryl sulfonyl indoles is reported. The reaction proceeds with high diastereoselectivity to provide the optically enriched spirocyclopentane-1,3'-indolenines in up to 74% yield and with up to 97% ee, which contains an all-carbon quaternary center and two tertiary stereocenters. The reaction involves a first conjugate addition of the carbon anion of zwitterionic π-allylpalladium complex from vinyl cyclopropane to the in situ formed unsaturated imine followed by a palladium-catalyzed intramolecular C3-allylation of indole.

Semaphoring is a transmembrane receptor which participates in many cytokine-mediated signal pathways that are closely related to the angiogenesis, occurrence and development of carcinoma. The present study was designed to access the effect of mono-antibody (mAb) guided radioimmunotherapy (RIT) on skin carcinoma and investigate the potential mechanisms. Semaphoring mAb was acquired from mice (Balb/c), purified with rProtein A column; purity, concentration and activity were tested with SDS-PAGE and indirect ELISA; specificity and expression on the cutanuem carcinoma line and tissue were tested by Western blotting; morphology change was assessed by microscopy. MTT assay and colony inhibition tests were carried out to test the influence on the proliferation of tumor cells; Western blotting was also carried out for expression of apoptosis-associated (caspase-3, Bax, Bcl-2) and proliferation-related (PI3K, p-Akt, Akt, p-ERK1/2, ERK1/2) proteins and analyse the change in signal pathways (PI3K/Akt and MEK/ERK). The purity of purified semaphorin mAb was 96.5% and the titer is about 1?106. Western blotting showed semaphoring mAb to have specifically binding stripes with semaphoring b1b2 protein, B16F10, and A431 cells at 39KDa, 100KDa and 130KDa, respectively. Positive expression was detected both in cutanuem carcinoma line and tissue and it mostly located in cell membranes. MMT assay revealed dose-relate and time-relate inhibitory effect of semaphorin mAb on A431 and B16F10. Colony inhibition tests also showed dose-relate inhibitory effects. Western blotting demonstrated the expression of apoptosis and proliferation-related protein and changes in signal pathway. In conclusion, we demonstrated that semaphorin is highly expressed on the tumor cell-surfaces and RIT with semaphorin mAb has effect in inhibiting proliferation and accelerating apoptosis of tumor cells.

Background. The objective of this paper is to demonstrate the effect of Gynostemma pentaphyllum extract on mouse dermal fibroblasts. Recent studies have shown that this plant may possess great antioxidant properties, which can be very beneficial in combating oxidative stress. Methods. Gynostemma pentaphyllum extract was prepared and mouse dermal fibroblasts were obtained and cultured as per our laboratory protocols. Twelve samples of cells were cultured under the same conditions and both negative and positive controls were established. Induction of oxidative stress was carried out using ultraviolet C (UVC) light. Viable cell count was carried out, using microscopy. The analysis of the overall results was processed using SPSS version 16.0. Results. Statistical analysis showed strong positive correlation between the concentration of Gynostemma pentaphyllum and the mean duration of cell viability (rs = 1), with a high level of statistical significance (P < 0.01). Likewise, strong positive correlation existed between trials of cell viability (rs = 0.988-1), with statistical significance (P < 0.01). Conclusion. Gynostemma pentaphyllum extract prolongs viability of mouse dermal fibroblasts damaged by UVC light-induced oxidative stress. The results show the potential benefits of this extract on dermal cell aging.

A concise route to valuable sulfamate-fused 2,6-disubstituted piperidin-4-ones or 2,3-dihydropyridin-4(1H)-ones in good yield with high diastereo- and enantioselectivity is presented. The combination of chiral primary amine and o-fluorobenzoic acid efficiently promoted an asymmetric [4 + 2] cycloaddition reaction of N-sulfonylimines and enones or ynones. The cycloaddition reaction between cyclic N-sulfonylimines and ynones is first reported.

A highly stereoselective one-pot reaction of aliphatic aldehydes and cyanoacrylamides has been developed. The one-pot reaction includes an organocatalytic Michael addition followed by an intramolecular hemiaminalization. After reduction, optically enriched 2-piperidinones with three contiguous chiral centers were obtained in up to 95% yield and 9:1 dr with 99% ee.

Highly enantioselective cross-aldol reactions between acetaldehyde and activated acyclic ketones are reported for the first time. Various acyclic ketones, such as saturated and unsaturated keto esters, reacted with acetaldehyde in the presence of a chiral primary amine and a Brønsted acid to afford optically enriched tertiary alcohols in good yields and with excellent enantioselectivities. Trifluoromethyl ketones were tolerable under the reaction conditions, thereby affording the trifluoromethyl carbinol in good-to-excellent yields and enantioselectivities. Structural modification of the chiral amines from the same chiral source switched the stereoselectivity of the products. The utility of aldol chemistry was demonstrated in the brief synthesis of functionally enriched δ-lactones. Theoretical calculations on the transition-state structure indicated that the protonated tertiary amine could effectively activate the carbonyl group of a keto ester to promote the addition process through hydrogen-bonding interaction and, simultaneously, provide an appropriate attacking pattern for the approach of the keto ester to the enamine, which is formed from acetaldehyde and the chiral catalyst, on a particular face, resulting in high enantioselectivity., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Objective: To investigate the epidemic trend and features of male genital herpes (GH) in Tianjin., Methods: We statistically analyzed the epidemiological data of the male GH patients received at the Venereal Disease Clinic of Tianjin Medical University General Hospital from 2006 to 2010., Results: A total of 130 cases of male GH were reported from 2006 to 2010, ranging in age from 18 to 76 years, with 31.54% aged at 30-39 years. Most of the patients were factory workers (30.77%) and clerks (30.00%). Those with high school education accounted for 61.54%, and those with college education 32.31%. The sex partners of the patients were mostly waitresses (60%)., Conclusion: The epidemic of GH has not been effectively controlled in Tianjin. New measures have to be developed targeting the changed epidemiological features of GH for better prevention and control of the disease.

Background: There have been limited data on molecular epidemiology of syphilis in China. This study aimed to analyze strain type distribution of Treponema pallidum causing early syphilis across geographic areas in China using an enhanced method., Methods: Genital samples were collected from patients in East, South, and North China. Positive DNA of T. pallidum was analyzed by arp, tpr, and tp0548 genes., Results: Sufficient DNA for full molecular typing existed in 197 of 324 samples, and 27 strain types were identified. A range of 3 to 20 repeats (except 4, 11, and 19 repeats) and 25 repeats were found for the 60-bp tandem repeats of the arp gene. This was the first time the 9 and 25 repeats were detected. For the RFLP analysis of the tpr genes, patterns a, d, h, j, and l were identified. This was the first time the h, j, and l patterns were observed in China. For the sequence analysis of the tp0548 gene, sequences c, e, and f were identified. Strain type distribution was significantly different across geographic areas (χ² = 20.6, P = 0.006). Overall, 14d/f was most predominant (39% of fully typed samples, 95% CI = 32%-46%); 13d/f, 15d/f, and 16d/f were next most common (each 13% of fully typed samples, 95% CI = 9%-18%)., Conclusions: There is substantial genetic diversity of T. pallidum in China. The broad and ununiform distribution of strain types may reflect differences in regional sexual network patterns. Predominance of few strain types may indicate a linked transmission.

Highly diastereoselective and enantioselective catalytic capture of chiral zinc enolates using nitroolefins as electrophiles is described. The tandem products γ-nitro ketones were obtained in good yields with high diastereoselectivities and enantioselectivities. The γ-nitro ketones were readily hydrogenated to the optically enriched and diastereomerically pure chiral pyrrolidines with four contiguous stereocentres under mild conditions.

Highly efficient asymmetric aldol reactions between α,β-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of substrates were tolerable in the present catalytic system.

The chiral bimetallic oxovanadium complexes have been designed for the enantioselective oxidative coupling of 2-naphthols bearing various substituents at C6 and/or C7. The chirality transferring from the amino acid to the axis of the biphenyl in oxovanadium complexes 2 was found to occur with the use of UV and CD spectra and DFT calculation. The homo-coupling reaction with oxygen as the oxidant was promoted by 5 mol % of an oxovanadium complex derived from L-isoleucine and achiral biphenol to afford binaphthols in nearly quantitative yields with high enantioselectivities of up to 98% ee. An oxovanadium complex derived from L-isoleucine and H8-binaphthol is highly efficient at catalyzing the air-oxidized coupling of 2-naphthols with excellent enantioselectivities of up to 97% ee. 51V NMR study shows that the oxovanadium complexes have two vanadium(V) species. Kinetic studies, the cross-coupling reaction, and HRMS spectral studies on the reaction have been carried out and illustrate that two vanadium(V) species are both involved in catalysis and that the coupling reaction undergoes a radical-radical mechanism in an intramolecular manner. Quantum mechanical calculations rationalize the importance of the cooperative effects of the axial chirality matching S-amino acids on the stereocontrol of the oxidative coupling reaction. The application of the transformation in the preparation of chiral ligands and conjugated polymers confirms the importance of the current process in organic synthesis.

Highly enantioselective aldol reactions of aldehydes with cyclic ketones catalyzed by a primary amine derived from cinchonine are reported. Aromatic aldehydes reacted with various cyclic ketones cleanly to afford the anti-aldol adducts in up to 99% yield, with good diastereoselectivities (up to 9 : 1) and excellent enantioselectivities (up to 99% ee).

A family of optically pure 7,7'-disubsituted-2,2'-dihydroxy-1,1'-dinaphthyls have been conveniently prepared from easily accessible 7-alloxyl-2-naphthol by reaction sequences beginning with the asymmetric oxidative coupling and followed by key synthetic steps including deprotection, alkylation, and Suzuki coupling. Application of these binaphthols in catalytic phenylacetylene addition to aldehydes resulted in excellent enantioselectivities.