Rational design of new bioisosteres through introduction of high-value functional groups to bicyclo[1.1.1]pentane(BCP)is of particular use for drug discovery.Disclosed herein is the first access to valuable fluoroalky...Rational design of new bioisosteres through introduction of high-value functional groups to bicyclo[1.1.1]pentane(BCP)is of particular use for drug discovery.Disclosed herein is the first access to valuable fluoroalkylthio(seleno)-functionalized BCPs.A range of SCF3,SCF2H,SCFH2,SeCF3,SeC4F9,and SeC8F17 groups are readily incorporated to BCPs under mild conditions.Concomitant installation of a sulfone provides a platform for incorporation of the BCP motif to bioactive molecules.This practical protocol features novel BCP scaffolds,broad substrate scope,excellent atom-economy,simple operation,and gramscale preparation.展开更多
It is well known that gas oils from oilsands bitumen are difficult to hydrotreat. In order to develop the most appropriate flow sheet and operating conditions, a thorough knowledge of the molecular structure and beha...It is well known that gas oils from oilsands bitumen are difficult to hydrotreat. In order to develop the most appropriate flow sheet and operating conditions, a thorough knowledge of the molecular structure and behaviour of bitumen and its gas oil products is needed. In this work, the gas oil samples are fractionated in an attempt to isolate and identify the problematic molecular species for hydrotreating. It is found that the major nitrogen sources in coker gas oils are associated with relatively small pentane insoluble species and an even smaller, highly polar, hexane insoluble species. Structural information obtained for these fractions indicates that they are formed during the cracking of resin molecules. Nitrogen speciation shows that the pyrroles are the primary nitrogen type, with pyridines also being an important species. Both nitrogen species are undesirable in the hydrotreating process. Pyrroles in particular are subject to polymerisation, producing gums and sediments that foul filters and other equipment while pyridines can directly deactivate the hydrotreating catalyst.展开更多
The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an ...The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an autoclave. The product distribution of n-pentane isomerization could be improved by such improvers as benzene, cyelohexane, and methyl cyclohexane at the expense of conversion of n-pentane. The optimal product distribution improver was determined to be cyclohexane. The yield of isomerate and the selectivity of liquid isoalkanes increased, whereas the conversion of n-pentane decreased, with increasing cyclohexane amount. At the same conversion of n-pentane, the research octane number (RON) of liquid product, with cyclohexane amount of 0.5 wt%, was about 1.3 higher than that without cyclohexane. At the same reaction conditions, the presence of cyclohexane enhanced the yield of isomerate, the selectivity of liquid isoalkanes, and the RON of the liquid product, but reduced the conversion of n-pentane.展开更多
3,3'-Bis(5-(N-(4-hydroxylphenyl)imidomethyl)pyrrol-2-yl)pentane 1 has been synthesized and characterized. The crystal of its methanol complex, 1·(CH3OH)2, belongs to the orthorhombic system, space group ...3,3'-Bis(5-(N-(4-hydroxylphenyl)imidomethyl)pyrrol-2-yl)pentane 1 has been synthesized and characterized. The crystal of its methanol complex, 1·(CH3OH)2, belongs to the orthorhombic system, space group Pccn with a = 18.094(2), b = 11.6890(16), c = 13.3629(19) , V = 2826.3(7) 3, Z = 8, C14.5H18N2O2, Mr = 252.31, Dc = 1.186 g/cm3, F(000) = 1080 and μ(MoKα) = 0.080 mm-1. The final R = 0.0662 and wR = 0.1801 for 1908 observed reflections with I 2σ(I), and R = 0.0800 and wR = 0.1948 for all reflections. In the solid state, bridged by included methanol molecules, the molecules of compound 1 form interpenetrated grid structure through N–H···O and O–H···O hydrogen bonds.展开更多
This study focuses on the effects of reducing solvents used in the preparation of vanadyl pyrophosphate (VPO), and ZrO2 and (ZrO)2P2O7 promoters on the structure and catalytic performance of VPO catalysts. The VPO...This study focuses on the effects of reducing solvents used in the preparation of vanadyl pyrophosphate (VPO), and ZrO2 and (ZrO)2P2O7 promoters on the structure and catalytic performance of VPO catalysts. The VPO catalysts were prepared by the following steps: 1) Formation of vanadium phosphate by the reaction of V2O5 and H3PO4, 2) Synthesis of VPO precursor through the reduction of vanadium phosphate by reducing solvents, and 3) Activation of the precursor. For Zr promoted VPO, Zr was added to the precursor before activation. The P/V atomic ratios of different VPO catalysts, which were prepared by using different reducing solvents, were different. The precursor prepared by using isobutanol or isobutanol-benzyl alcohol contained VO(H2PO4)2 and VOHPO4·0.5H2O. The precursor prepared by using hexanol also contained VO(H2PO4)2 and VOHPO4·0.5H2O crystal phases, but the amount of VOHPO4·0.5H2O was much less than that of VO(H2PO4)2. After activation, all the VPO catalysts, prepared by using different reducing solvents, contained only the (VO)2P2O7 crystal phase. The VPO prepared by using isobutanol-petroleum ether as reducing solvent was the most active, while the VPO prepared by using hexanol had the lowest activity. Nevertheless, their total selectivity to phthalic and maleic anhydrides was almost the same. Both ZrO2 and (ZrO)2P2O7 promoters increased the activity and selectivity of VPO, but ZrO2 promoter increased the activity of VPO more drastically than (ZrO)2P2O7 promoter.展开更多
Schizophrenia is a common and debilitating mental illness. The disorder is thought to be developmental in origin, with oxidative stress being implicated as possible pathophysiological mechanism. Breath alkanes provide...Schizophrenia is a common and debilitating mental illness. The disorder is thought to be developmental in origin, with oxidative stress being implicated as possible pathophysiological mechanism. Breath alkanes provide a non-invasive means to assess oxidative stress, with ethane levels reportedly increased in medicated patients with schizophrenia. It is possible, however, that the psychotropic medications used to treat the disorder result in elevated breath ethane levels. We have therefore measured the concentration of ethane and pentane, markers of oxidative stress, in the breath of currently unmedicated patients with schizophrenia. Alveolar breath samples were collected, applied to thermal desorption tubes, and analyzed using a combination of two-stage thermal de-sorption, gas chromatography and mass spectrometry. Compared to healthy controls ethane and pentane levels were found to be elevated in patients with schizophrenia, while levels of butane were normal. Our data support the notion that oxidative stress is increased in schizophrenia and that this is unlikely to be a consequence of antipsychotic medications. In addition, breath alkane analysis may represent a rapid and non-invasive means to monitor oxidative stress occurring in schizophrenia.展开更多
Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol a...Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (<strong>1</strong>) melts at higher temperature (202°C) than compound (<strong>2</strong>) (100<span style="white-space:normal;">°</span>C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.展开更多
Pentafluorosulfanylated(SF_(5^(-))) aromatics have shown great potential in drugs, and the bioisosteric replacement of aromatic ring with bicyclo[1.1.1]pentane(BCP) unit has attracted considerable attention recently. ...Pentafluorosulfanylated(SF_(5^(-))) aromatics have shown great potential in drugs, and the bioisosteric replacement of aromatic ring with bicyclo[1.1.1]pentane(BCP) unit has attracted considerable attention recently. Consequently, pentafluorosulfanylated bicyclo[1.1.1]pentanes(SF_(5^(-))BCPs) should have application in the realm of drug discovery. In this study, a one-pot iodopentafluorosulfanylation of [1.1.1]propellane with SF_(5)Cl and CH_(2)I_(2)for the practical synthesis of iodopentafluorosulfanylated bicyclo[1.1.1]pentane(SF_(5^(-))BCP-I) was developed. SF_(5^(-))BCP-I was the first example of SF_(5^(-))BCPs that could be transformed. The first general method to access SF_(5^(-))substituted bicyclo[1.1.1]pentane derivatives was demonstrated through photoredox-catalyzed radical addition of SF_(5^(-))BCP-I to alkenes and alkynes.展开更多
Some 11 novel series of biological markers, aryl isoprenoids, have been found in Sunniland sedimentary organic matter (both oil and its source rock) of the South Florida Basin (USA). All of them have the same homologo...Some 11 novel series of biological markers, aryl isoprenoids, have been found in Sunniland sedimentary organic matter (both oil and its source rock) of the South Florida Basin (USA). All of them have the same homologous key ions m/z 91+14n (n=0—10). In this paper, only one of these homologous series, 2, 3, 6-trimethylphenylisoprenoids, will be discussed organic-geochemically. Two new maturity indicators, ΣHⅠ/ΣHⅡ and ΣHB/ΣHA, have been put forward, and it is suggested that these novel biomarker compounds can be used as indicators of organic facies and maturity of sedimentary organic matter.展开更多
As a highly strained small molecule,[1.1.1]propellane has been widely used in various synthetic transformations owing to the exceptional reactivity of the central bond between the two bridgehead carbons.Utilizing stra...As a highly strained small molecule,[1.1.1]propellane has been widely used in various synthetic transformations owing to the exceptional reactivity of the central bond between the two bridgehead carbons.Utilizing strain-release approaches,the rapid development of strategies for the construction of bicyclo[1.1.1]pentane(BCP)and cyclobutane derivatives using[1.1.1]propellane as the starting material has been witnessed in the past few years.In this review,we highlight the most recent advances in this field.Accordingly,the reactivity of[1.1.1]p ropellane can be divided into three pathways,including radical,anionic and transition metal-catalyzed pathways under appropriate conditions.展开更多
基金supported by the National Natural Science Foundation of China(21722205,21971173)the Project of Scientific and Technologic Infrastructure of Suzhou(SZS201905)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Rational design of new bioisosteres through introduction of high-value functional groups to bicyclo[1.1.1]pentane(BCP)is of particular use for drug discovery.Disclosed herein is the first access to valuable fluoroalkylthio(seleno)-functionalized BCPs.A range of SCF3,SCF2H,SCFH2,SeCF3,SeC4F9,and SeC8F17 groups are readily incorporated to BCPs under mild conditions.Concomitant installation of a sulfone provides a platform for incorporation of the BCP motif to bioactive molecules.This practical protocol features novel BCP scaffolds,broad substrate scope,excellent atom-economy,simple operation,and gramscale preparation.
文摘It is well known that gas oils from oilsands bitumen are difficult to hydrotreat. In order to develop the most appropriate flow sheet and operating conditions, a thorough knowledge of the molecular structure and behaviour of bitumen and its gas oil products is needed. In this work, the gas oil samples are fractionated in an attempt to isolate and identify the problematic molecular species for hydrotreating. It is found that the major nitrogen sources in coker gas oils are associated with relatively small pentane insoluble species and an even smaller, highly polar, hexane insoluble species. Structural information obtained for these fractions indicates that they are formed during the cracking of resin molecules. Nitrogen speciation shows that the pyrroles are the primary nitrogen type, with pyridines also being an important species. Both nitrogen species are undesirable in the hydrotreating process. Pyrroles in particular are subject to polymerisation, producing gums and sediments that foul filters and other equipment while pyridines can directly deactivate the hydrotreating catalyst.
基金support was provided by the National Science Foundation of China(Grant Nos.20806091,20976194,and 21036008)
文摘The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an autoclave. The product distribution of n-pentane isomerization could be improved by such improvers as benzene, cyelohexane, and methyl cyclohexane at the expense of conversion of n-pentane. The optimal product distribution improver was determined to be cyclohexane. The yield of isomerate and the selectivity of liquid isoalkanes increased, whereas the conversion of n-pentane decreased, with increasing cyclohexane amount. At the same conversion of n-pentane, the research octane number (RON) of liquid product, with cyclohexane amount of 0.5 wt%, was about 1.3 higher than that without cyclohexane. At the same reaction conditions, the presence of cyclohexane enhanced the yield of isomerate, the selectivity of liquid isoalkanes, and the RON of the liquid product, but reduced the conversion of n-pentane.
基金supported by the National Natural Science Foundation of China (No. 20702038)
文摘3,3'-Bis(5-(N-(4-hydroxylphenyl)imidomethyl)pyrrol-2-yl)pentane 1 has been synthesized and characterized. The crystal of its methanol complex, 1·(CH3OH)2, belongs to the orthorhombic system, space group Pccn with a = 18.094(2), b = 11.6890(16), c = 13.3629(19) , V = 2826.3(7) 3, Z = 8, C14.5H18N2O2, Mr = 252.31, Dc = 1.186 g/cm3, F(000) = 1080 and μ(MoKα) = 0.080 mm-1. The final R = 0.0662 and wR = 0.1801 for 1908 observed reflections with I 2σ(I), and R = 0.0800 and wR = 0.1948 for all reflections. In the solid state, bridged by included methanol molecules, the molecules of compound 1 form interpenetrated grid structure through N–H···O and O–H···O hydrogen bonds.
文摘This study focuses on the effects of reducing solvents used in the preparation of vanadyl pyrophosphate (VPO), and ZrO2 and (ZrO)2P2O7 promoters on the structure and catalytic performance of VPO catalysts. The VPO catalysts were prepared by the following steps: 1) Formation of vanadium phosphate by the reaction of V2O5 and H3PO4, 2) Synthesis of VPO precursor through the reduction of vanadium phosphate by reducing solvents, and 3) Activation of the precursor. For Zr promoted VPO, Zr was added to the precursor before activation. The P/V atomic ratios of different VPO catalysts, which were prepared by using different reducing solvents, were different. The precursor prepared by using isobutanol or isobutanol-benzyl alcohol contained VO(H2PO4)2 and VOHPO4·0.5H2O. The precursor prepared by using hexanol also contained VO(H2PO4)2 and VOHPO4·0.5H2O crystal phases, but the amount of VOHPO4·0.5H2O was much less than that of VO(H2PO4)2. After activation, all the VPO catalysts, prepared by using different reducing solvents, contained only the (VO)2P2O7 crystal phase. The VPO prepared by using isobutanol-petroleum ether as reducing solvent was the most active, while the VPO prepared by using hexanol had the lowest activity. Nevertheless, their total selectivity to phthalic and maleic anhydrides was almost the same. Both ZrO2 and (ZrO)2P2O7 promoters increased the activity and selectivity of VPO, but ZrO2 promoter increased the activity of VPO more drastically than (ZrO)2P2O7 promoter.
文摘Schizophrenia is a common and debilitating mental illness. The disorder is thought to be developmental in origin, with oxidative stress being implicated as possible pathophysiological mechanism. Breath alkanes provide a non-invasive means to assess oxidative stress, with ethane levels reportedly increased in medicated patients with schizophrenia. It is possible, however, that the psychotropic medications used to treat the disorder result in elevated breath ethane levels. We have therefore measured the concentration of ethane and pentane, markers of oxidative stress, in the breath of currently unmedicated patients with schizophrenia. Alveolar breath samples were collected, applied to thermal desorption tubes, and analyzed using a combination of two-stage thermal de-sorption, gas chromatography and mass spectrometry. Compared to healthy controls ethane and pentane levels were found to be elevated in patients with schizophrenia, while levels of butane were normal. Our data support the notion that oxidative stress is increased in schizophrenia and that this is unlikely to be a consequence of antipsychotic medications. In addition, breath alkane analysis may represent a rapid and non-invasive means to monitor oxidative stress occurring in schizophrenia.
文摘Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (<strong>1</strong>) melts at higher temperature (202°C) than compound (<strong>2</strong>) (100<span style="white-space:normal;">°</span>C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.
基金supported by the National Natural Science Foundation of China (21991121)the National Key Research and Development Program of China (2021YFF0701700)。
文摘Pentafluorosulfanylated(SF_(5^(-))) aromatics have shown great potential in drugs, and the bioisosteric replacement of aromatic ring with bicyclo[1.1.1]pentane(BCP) unit has attracted considerable attention recently. Consequently, pentafluorosulfanylated bicyclo[1.1.1]pentanes(SF_(5^(-))BCPs) should have application in the realm of drug discovery. In this study, a one-pot iodopentafluorosulfanylation of [1.1.1]propellane with SF_(5)Cl and CH_(2)I_(2)for the practical synthesis of iodopentafluorosulfanylated bicyclo[1.1.1]pentane(SF_(5^(-))BCP-I) was developed. SF_(5^(-))BCP-I was the first example of SF_(5^(-))BCPs that could be transformed. The first general method to access SF_(5^(-))substituted bicyclo[1.1.1]pentane derivatives was demonstrated through photoredox-catalyzed radical addition of SF_(5^(-))BCP-I to alkenes and alkynes.
文摘Some 11 novel series of biological markers, aryl isoprenoids, have been found in Sunniland sedimentary organic matter (both oil and its source rock) of the South Florida Basin (USA). All of them have the same homologous key ions m/z 91+14n (n=0—10). In this paper, only one of these homologous series, 2, 3, 6-trimethylphenylisoprenoids, will be discussed organic-geochemically. Two new maturity indicators, ΣHⅠ/ΣHⅡ and ΣHB/ΣHA, have been put forward, and it is suggested that these novel biomarker compounds can be used as indicators of organic facies and maturity of sedimentary organic matter.
基金the National Natural Science Foundation of China(Nos.21672037 and 21532001)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2019R01005)。
文摘As a highly strained small molecule,[1.1.1]propellane has been widely used in various synthetic transformations owing to the exceptional reactivity of the central bond between the two bridgehead carbons.Utilizing strain-release approaches,the rapid development of strategies for the construction of bicyclo[1.1.1]pentane(BCP)and cyclobutane derivatives using[1.1.1]propellane as the starting material has been witnessed in the past few years.In this review,we highlight the most recent advances in this field.Accordingly,the reactivity of[1.1.1]p ropellane can be divided into three pathways,including radical,anionic and transition metal-catalyzed pathways under appropriate conditions.