Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O...Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O-containing value-added chemicals thereby replacing the traditional petroleum-based approaches.The scope for developing efficient bifunctional catalysts and establishing mild reaction conditions for upgrading furfurals to cyclic compounds has stimulated immense deliberation in recent years.Extensive efforts have been made toward developing catalysts for multiple tandem conversions,including those with various metals and supports.In this scientific review,we aim to summarize the research progress on the synergistic effect of the metal-acid sites,including simple metal-supported acidic supports,adjacent metal acid sites-supported catalysts,and in situ H_(2)-modified bifunctional catalysts.Distinctively,the catalytic performance,catalytic mechanism,and future challenges for the hydrogenative rearrangement are elaborated in detail.The methods highlighted in this review promote the development of C_(5) cyclic compound synthesis and provide insights to regulate bifunctional catalysis for other applications.展开更多
α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cycli...α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.展开更多
Various cyclic N_8 isomers are considered at the levels of B3 LYP/6-311++G(d,p) and B3 LYP/c PVTZ. Some energies and molecular orbital properties are obtained. The structures are found to be stable in the singlet stat...Various cyclic N_8 isomers are considered at the levels of B3 LYP/6-311++G(d,p) and B3 LYP/c PVTZ. Some energies and molecular orbital properties are obtained. The structures are found to be stable in the singlet state but mostly unstable in the triplet. The heats of formation values calculated by means of T1 recipe reveals that they are highly endothermic. NICS(0) values have been calculated and aromaticity/antiaromaticity of the rings are discussed. Additionally, theoretical IR,UV-VIS spectra and the calculated impulse values have been obtained.展开更多
Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of ...Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation （H＋, NH4＋） and the peripheral atoms （Mo, W） on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms （Mo） were replaced by their homologous （W）, the polymerization rate increased twofold. As for the viscosity average molecular weight （My） of polymer products, it was found that the high molecular weight （7930） was obtained by using H3PW12O40·13H2O. The molecular weight （My） obtained by H3PMo12O40·13H2O and （NH4）H3PMo12O40·13H2O was 6470 and 6810, respectively.展开更多
通过合理假设,从谢苗诺夫(Semenov)热爆炸理论和8个非等温动力学方程,导出了估算含能材料(EMs)热爆炸临界温度(Tb)的2个通式和它们的6个派生式。从EMs的非等温DSC曲线可获得DSC曲线偏离基线的起始温度(T0)、onset温度(Tei)和放热分解反...通过合理假设,从谢苗诺夫(Semenov)热爆炸理论和8个非等温动力学方程,导出了估算含能材料(EMs)热爆炸临界温度(Tb)的2个通式和它们的6个派生式。从EMs的非等温DSC曲线可获得DSC曲线偏离基线的起始温度(T0)、onset温度(Tei)和放热分解反应的动力学参数。由方程T0ior ei=T00 or e0+a1βi+a2βi2+…+aL-2βiL-2,i=1,2,…,L可得到T00和Te0值,随后用6个派生式可计算Tb值。对1,4,5,8-四硝基-1,4,5,8-四氮杂双呋咱[3,4-c:3′,4′-h]十氢化萘,1,4,5,8-四氮杂双呋咱[3,4-c:3′,4′-h]十氢化萘,1,3,4-三硝基咪唑烷酮[4,5-b]呋咱[3,4-e]哌嗪,咪唑烷酮[4,5-b]呋咱[3,4-e]哌嗪,1,3,4,8-四硝基咪唑烷酮[4,5-b]呋咱[3,4-e]哌嗪,1,4,5,8-四硝基-1,4,5,8-四氮杂萘呋咱[3,4-b]十氢化萘,1,3,5-三硝基-1,3,5-三氮杂呋咱[3,4-f]环庚烷,由6个派生式所得的Tb值甚接近。展开更多
A novel cadmium(Ⅱ) isothiocyanate complex [Cd(N-MeIM)2(SCN)2]n (N-MeIM=N-methylimidazole) has been prepared and characterized by spectroscopic analysis and crystallographic method. The title compound crystallize in t...A novel cadmium(Ⅱ) isothiocyanate complex [Cd(N-MeIM)2(SCN)2]n (N-MeIM=N-methylimidazole) has been prepared and characterized by spectroscopic analysis and crystallographic method. The title compound crystallize in the Triclinic system, space group P1, with lattice parameters a=0.589 50(12) nm, b=0.785 70(16) nm, c=0.882 00(18) nm, α=110.98(3)°, β=106.49(3)°, γ=95.08(3)°, and Z=1. The title compound exhibits an infinite chain structure in which each pair of Cd atoms is bridged by two η-1,3-SCN- groups. The unique Cd atom lies on an inversion centre and the coordination sphere is completed by two N-MeIM N atoms to form a CdS2N4 octahedron. The polymeric chains are further extended into three-dimensional network via π...π stackings interactions between the imidazole rings. The cyclic voltammetry behaviors of the compound on glass carbon electrode showed a typical irreversible process. CCDC: 265283.展开更多
基金support from the National Natural Science Foundation of China (Nos. 22178158, 52162014 and 22065024)Science and Technology Project of Education Department of Jiangxi Province (No. GJJ2200402)+3 种基金Jiangxi Provincial Natural Science Foundation (No. 20224BAB213023)the Outstanding Youth Science Fund Project of Jiangxi Province (No. 20224ACB213008)the Jiangxi Provincial Double Thousand Talents Plan-Youth Program (No. S2021GDQN0947)Natural Science Foundation of Chongqing (No. 2023NSCQ-MSX0052)
文摘Hydrogenative rearrangement of biomas s-derived furfurals(furfural and 5-hydroxymethyl furfural) to C_(5) cyclic compounds(such as cyclopentanones and cyclopentanols) offers an expedient reaction route for acquiring O-containing value-added chemicals thereby replacing the traditional petroleum-based approaches.The scope for developing efficient bifunctional catalysts and establishing mild reaction conditions for upgrading furfurals to cyclic compounds has stimulated immense deliberation in recent years.Extensive efforts have been made toward developing catalysts for multiple tandem conversions,including those with various metals and supports.In this scientific review,we aim to summarize the research progress on the synergistic effect of the metal-acid sites,including simple metal-supported acidic supports,adjacent metal acid sites-supported catalysts,and in situ H_(2)-modified bifunctional catalysts.Distinctively,the catalytic performance,catalytic mechanism,and future challenges for the hydrogenative rearrangement are elaborated in detail.The methods highlighted in this review promote the development of C_(5) cyclic compound synthesis and provide insights to regulate bifunctional catalysis for other applications.
基金We gratefully acknowledge financial support from the National Science of Foundation of China(81960631)the Yunnan Fundamental Research Project(202001AS070038)+1 种基金the Top Young Talent of Ten Thousand Talents Program of Yunnan Province(R.Zhan and L.-D Shao)the Start-up Fund of Yunnan University of Chinese Medicine(2019YZG03).
文摘α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.
文摘Various cyclic N_8 isomers are considered at the levels of B3 LYP/6-311++G(d,p) and B3 LYP/c PVTZ. Some energies and molecular orbital properties are obtained. The structures are found to be stable in the singlet state but mostly unstable in the triplet. The heats of formation values calculated by means of T1 recipe reveals that they are highly endothermic. NICS(0) values have been calculated and aromaticity/antiaromaticity of the rings are discussed. Additionally, theoretical IR,UV-VIS spectra and the calculated impulse values have been obtained.
基金supported by the Deanship of Scientific Research,King Saud University(No.M/202) and SABIC Company
文摘Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation （H＋, NH4＋） and the peripheral atoms （Mo, W） on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms （Mo） were replaced by their homologous （W）, the polymerization rate increased twofold. As for the viscosity average molecular weight （My） of polymer products, it was found that the high molecular weight （7930） was obtained by using H3PW12O40·13H2O. The molecular weight （My） obtained by H3PMo12O40·13H2O and （NH4）H3PMo12O40·13H2O was 6470 and 6810, respectively.
基金National Natural Science Foundation of China(No.20573098)Science and Technology Foundation of the National Defence Key Laboratory of Propellant and Explosive Combustion of China(9140C3501050701)
文摘通过合理假设,从谢苗诺夫(Semenov)热爆炸理论和8个非等温动力学方程,导出了估算含能材料(EMs)热爆炸临界温度(Tb)的2个通式和它们的6个派生式。从EMs的非等温DSC曲线可获得DSC曲线偏离基线的起始温度(T0)、onset温度(Tei)和放热分解反应的动力学参数。由方程T0ior ei=T00 or e0+a1βi+a2βi2+…+aL-2βiL-2,i=1,2,…,L可得到T00和Te0值,随后用6个派生式可计算Tb值。对1,4,5,8-四硝基-1,4,5,8-四氮杂双呋咱[3,4-c:3′,4′-h]十氢化萘,1,4,5,8-四氮杂双呋咱[3,4-c:3′,4′-h]十氢化萘,1,3,4-三硝基咪唑烷酮[4,5-b]呋咱[3,4-e]哌嗪,咪唑烷酮[4,5-b]呋咱[3,4-e]哌嗪,1,3,4,8-四硝基咪唑烷酮[4,5-b]呋咱[3,4-e]哌嗪,1,4,5,8-四硝基-1,4,5,8-四氮杂萘呋咱[3,4-b]十氢化萘,1,3,5-三硝基-1,3,5-三氮杂呋咱[3,4-f]环庚烷,由6个派生式所得的Tb值甚接近。
文摘A novel cadmium(Ⅱ) isothiocyanate complex [Cd(N-MeIM)2(SCN)2]n (N-MeIM=N-methylimidazole) has been prepared and characterized by spectroscopic analysis and crystallographic method. The title compound crystallize in the Triclinic system, space group P1, with lattice parameters a=0.589 50(12) nm, b=0.785 70(16) nm, c=0.882 00(18) nm, α=110.98(3)°, β=106.49(3)°, γ=95.08(3)°, and Z=1. The title compound exhibits an infinite chain structure in which each pair of Cd atoms is bridged by two η-1,3-SCN- groups. The unique Cd atom lies on an inversion centre and the coordination sphere is completed by two N-MeIM N atoms to form a CdS2N4 octahedron. The polymeric chains are further extended into three-dimensional network via π...π stackings interactions between the imidazole rings. The cyclic voltammetry behaviors of the compound on glass carbon electrode showed a typical irreversible process. CCDC: 265283.
