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C23H17NO4, orthorhombic, P212121 (no. 29), a = 26.3525(8) Å, b = 3.88640(10) Å, c = 34.8871(10) Å, V = 3573.01(18) Å3, Z = 8, Rgt(F) = 0.0419, wRref(F2) = 0.1086, T = 180 K.

Keywords: chiral phosphoric acid; organocatalysis; cycloaddition; alkenes; alkynes EN chiral phosphoric acid organocatalysis cycloaddition alkenes alkynes 1200 1214 15 06/19/23 20230704 NES 230704 1 Introduction Asymmetric cycloaddition reaction is the most powerful strategy for the construction of various enantioenriched carbocycles and heterocycles, [1] because it provides an efficient and completely atom-economical route from simple precursors. In order to achieve this goal, we needed to overcome the following issues: (1) realization of efficient cycloaddition of alkynes with appropriate partners; (2) the installation of suitable groups onto alkynes to avoid free rotation around the potential C-C axes; (3) the choice of a competent chiral catalyst to promote the designed cycloaddition reactions and to control the stereoselectivity. 3 CPA-Catalyzed Cycloaddition of Alkynes Although the CPA-catalyzed cycloaddition of alkenes have been well documented, the CPA-catalyzed asymmetric cycloaddition reaction of alkynes is still lacking. On the other hand, the cycloaddition of alkynylnaphthols with imines proceeded via a sequential [4+2] cycloaddition, an alkyne-type Povarov cycloaddition, and an auto-oxidation reaction. [Extracted from the article]

C20H19Cl4N3O3S, monoclinic, P21/c (no. 14), a = 14.2134(9) Å, b = 21.4083(13) Å, c = 7.6709(5) Å, β = 99.260(6)°, V = 2303.7(2) Å3, Z = 4, Rgt(F) = 0.0659, wRref(F2) = 0.1682, T = 180 K.

BACKGROUND: Diamondback moth, Plutella xylostella L., is a very important pest of cruciferous vegetables causing excessive economic losses worldwide. Bioactivities of halo‐, diazo‐, and cyclopropane acetates of P. xylostella sex pheromone have been evaluated using electrophysiology and enzyme inhibition assays. RESULTS: A total of 23 sex pheromone analogs of P. xylostella were designed and synthesized and the result shows that (11Z)‐hexadec‐11‐en‐1‐yl 2,2,2‐trifluoroacetate, (11Z)‐hexadec‐11‐en‐1‐yl 2,2,3,3,3‐pentafluoropropanoate, and (11Z)‐hexadec‐11‐en‐1‐yl trifluoromethanesulfonate elicited potential inhibitory effects at all doses tested in the electrophysiology and enzyme inhibition assays. Interference of locating the sex pheromone source was found strongest when these three analogs were mixed with the sex pheromone at a 10:1 ratio. In addition, field test showed that the rate of mating disruption was over 90% when (11Z)‐hexadec‐11‐en‐1‐yl 2,2,2‐trifluoroacetate or (11Z)‐hexadec‐11‐en‐1‐yl 2,2,3,3,3‐pentafluoropropanoate was mixed with the sex pheromone at a 10:1 ratio. CONCLUSION: Two sex pheromone antagonists were screen out by electrophysiology, enzyme inhibition assays, wind tunnel and field tests. We believe that these antagonists could be used to establish a novel eco‐friendly measure to control P. xylostella and provide evidence for clarifying the specific functions and molecular mechanisms of sex pheromone antagonists. © 2018 Society of Chemical Industry Diamondback moth Plutella xylostella L. is a very important pest of cruciferous vegetables causing excessive economic losses worldwide. Bioactivities of halo‐, diazo‐, and cyclopropane acetates of P. xylostellasex pheromone have been evaluated using electrophysiology and enzyme inhibition assays. [ABSTRACT FROM AUTHOR]

C23H17NO4, orthorhombic, P212121 (no. 29), a = 26.3525(8) Å, b = 3.88640(10) Å, c = 34.8871(10) Å, V = 3573.01(18) Å3, Z = 8, Rgt(F) = 0.0419, wRref(F2) = 0.1086, T = 180 K. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that geological or climatic events in the past promoted allopatric speciation of alpine plants in the Qinghai-Tibetan Plateau and adjacent region. However, few studies have been undertaken to examine whether such allopatric divergences also occurred within a morphologically uniform species. In the present study, we report the evolutionary history of an alpine shrub species, Hippophae tibetana, based on examining chloroplast DNA (cpDNA) and nuclear ribosomal internal transcribed spacer (ITS) DNA variations. We sequenced two cpDNA fragments ( trnL-F and trnS-G) and the nuclear ITS region in 183 individuals collected from 21 natural populations. Ten chlorotypes and 17 ITS types were identified. Phylogenetic analyses of both chlorotypes and ITS sequence variations suggested two distinct lineages distributed in the eastern and western region, respectively. On the basis of the fast and low plant substitution rates, these two lineages were estimated to have diverged from each other between 1 and 4 million years ago, during the period of the major glaciations and orogenic processes. In addition, ITS has undergone the accelerated evolution in two populations in the southern Himalaya isolated by the high mountains with a surprising accumulation of the private variations. The east-west split was also supported by an analysis of molecular variance, which partitioned around 91% of the total cpDNA variance between these two groups of populations. A single chlorotype was found for most populations in eastern or western region, suggesting a recent postglacial expansion within each region. Star-phylogeny and mismatch analyses of all chlorotypes within the eastern group of populations suggested an earlier regional expansion before the Last Glacial Maximum (LGM). The local fixture of the different chlorotypes in multiple populations suggested more than one refugia remained for eastern or western region. Coalescent tests rejected the hypothesis that all current populations originated from a single refugium during the LGM. Instead, they supported hypothesis that two lineages diverged before the late Pleistocene. These findings, when taken together, suggested that this species had experienced long allopatric divergence and recent regional range expansions in response to orogenic processes and the climate changes. The evolutionary history of this shrub species highlights importance of geographical isolations to the intraspecific divergence of alpine plants occurring in the world's ruff. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, , 37-50. [ABSTRACT FROM AUTHOR]

C20H19Cl4N3O3S, monoclinic, P21/c (no. 14), a = 14.2134(9) Å, b = 21.4083(13) Å, c = 7.6709(5) Å, β = 99.260(6)°, V = 2303.7(2) Å3, Z = 4, Rgt(F) = 0.0659, wRref(F2) = 0.1682, T = 180 K. [ABSTRACT FROM AUTHOR]

C23H17NO4, orthorhombic, P212121 (no. 29), a = 26.3525(8) Å, b = 3.88640(10) Å, c = 34.8871(10) Å, V = 3573.01(18) Å3, Z = 8, Rgt(F) = 0.0419, wRref(F2) = 0.1086, T = 180 K. [ABSTRACT FROM AUTHOR]

Synthesis of bicyclic scaffolds has gained significant attention in drug discovery due to their potential to mimic benzene bioisosteres. Here, we present a mild and scalable Sc(OTf) 3 -catalyzed [3+2] cycloaddition of bicyclo[1.1.0]butanes (BCBs) with ynamides, yielding a diverse array of polysubstituted 2-amino-bicyclo[2.1.1]hexenes in good to excellent yields. These products offer valuable starting materials for the construction of novel functionalized bicyclo[1.1.0]butanes. Preliminary mechanistic studies indicate that the reaction involves a nucleophilic addition of ynamides to bicyclo[1.1.0]butanes, followed by an intramolecular cyclization of in situ generated enolate and keteniminium ion. We expect that these findings will encourage utilization of complex bioisosteres and foster further investigation into BCB-based cycloaddition chemistry., (© 2024 Wiley-VCH GmbH.)

Background: The Chinese government has proposed cancer screening guidelines and launched 2 cancer screening programs to improve screening practices. However, the screening participation rates of Chinese women remain low. Exploring the factors affecting breast cancer screening to promote cancer screening is necessary., Objective: The aim of this study was to investigate women's satisfaction with healthcare providers and screening practices., Methods: A cross-sectional survey was conducted from November 2019 to April 2020 in Changchun, Jilin Province, China. The Medical Care Satisfaction Scale and SERVQUAL were used to quantify women's satisfaction with doctors and nurses, respectively., Results: Women's satisfaction with doctors (68.81 ± 11.08; range, 20-100) and with nurses (87.64 ± 16.17; range, 22-110) was moderate. Compared with women who had not participated in screening within the past 2 years, screened women reported higher satisfaction with doctors (P = .026) and nurses (P = .012). Older age (P = .004) was an independent predictor of women's satisfaction with doctors. Similarly, women's education level (P = .049), chronic disease history (P = .029), and physical examination history (P = .039) were 3 independent predictors of women's satisfaction with nurses., Conclusions: Future intervention strategies can not only increase the screening rates by providing existing intervention methods but also improve women's satisfaction with healthcare providers to promote screening practices., Implications for Practice: This article provides a theoretical basis for healthcare providers to increase female screening practices. It also provides references for improving existing intervention methods., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)