Chiral BINAM-derived selenide/achiral acid co-catalyzed atroposelective electrophilic sulfenylation of pyrrole derivatives has been realized for the first time.A variety of C-N axially chiral sulfur-containing pyrrole...Chiral BINAM-derived selenide/achiral acid co-catalyzed atroposelective electrophilic sulfenylation of pyrrole derivatives has been realized for the first time.A variety of C-N axially chiral sulfur-containing pyrrole derivatives were readily obtained in moderate to good yields with moderate to excellent enantioselectivities.This catalytic system involves sequential desymmetrization and kinetic resolution.展开更多
Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readi...Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities.As the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.展开更多
Facility location allocation(FLA) is one of the important issues in the logistics and transportation fields. In practice, since customer demands, allocations, and even locations of customers and facilities are usually...Facility location allocation(FLA) is one of the important issues in the logistics and transportation fields. In practice, since customer demands, allocations, and even locations of customers and facilities are usually changing, the FLA problem features uncertainty. To account for this uncertainty, some researchers have addressed the fuzzy profit and cost issues of FLA. However, a decision-maker needs to reach a specific profit, minimizing the cost to target customers. To handle this issue it is essential to propose an effective fuzzy cost-profit tradeoff approach of FLA. Moreover, some regional constraints can greatly influence FLA. By taking a vehicle inspection station as a typical automotive service enterprise example, and combined with the credibility measure of fuzzy set theory, this work presents new fuzzy cost-profit tradeoff FLA models with regional constraints. A hybrid algorithm integrating fuzzy simulation and genetic algorithms(GA) is proposed to solve the proposed models. Some numerical examples are given to illustrate the proposed models and the effectiveness of the proposed algorithm.展开更多
Enantioselective recognition in water remains an ongoing challenge in supramolecular chemistry but is routine in nature.Herein,we report the first enantiopure pair of biomimetic macrocyclic receptors with hydrogen bon...Enantioselective recognition in water remains an ongoing challenge in supramolecular chemistry but is routine in nature.Herein,we report the first enantiopure pair of biomimetic macrocyclic receptors with hydrogen bonding donors in their deep hydrophobic cavities.The chiral naphthotubes can be efficiently synthesized through a chirality-directed macrocyclization strategy and are able to discriminate the enantiomers of neutral chiral molecules in water.Density functional theory calculations reveal that the“three-point contact”model effectively explains their enantioselectivity.The differential noncovalent interactions inside the hydrophobic cavity are responsible for the enantioselective recognition.Moreover,these chiral naphthotubes are both fluorescent and circular dichroism(CD)-active.In CD spectroscopy,they have been demonstrated to have the ability to detect nonchromophoric,achiral molecules in water.And,the use of fluorescence spectroscopy has aided in the determination of the enantiomeric excess(ee)values of chiral molecules.The results and conclusions obtained with these chiral biomimetic receptors can be used to better understand enantioselective recognition in biological systems.展开更多
A facile method for the selective synthesis of pillar[6]arenes has been developed.Due to a strong electron do-nor-acceptor interaction between the electron-deficient naphthalene diimide and a precursor for the pillara...A facile method for the selective synthesis of pillar[6]arenes has been developed.Due to a strong electron do-nor-acceptor interaction between the electron-deficient naphthalene diimide and a precursor for the pillararene,1,4-diisobutoxy-2,5-bis(methoxymethyl)benzene,naphthalene diimide has been demonstrated to act as a template for selective synthesis of pillar[6]arene in a modest yield(30%).展开更多
基金Z.-M.Chen thanks National Natural Science Foundation of China(22071149,21871178)Natural Science Foundation of Shanghai(23ZR1428200)financial support.H.Ke thanks Natural Science Foundation of Jiangxi Province(20202ACBL213005)for financial support.
文摘Chiral BINAM-derived selenide/achiral acid co-catalyzed atroposelective electrophilic sulfenylation of pyrrole derivatives has been realized for the first time.A variety of C-N axially chiral sulfur-containing pyrrole derivatives were readily obtained in moderate to good yields with moderate to excellent enantioselectivities.This catalytic system involves sequential desymmetrization and kinetic resolution.
基金the National Natural Science Foundation of China(Nos.22071149,21871178)the Natural Science Foundation of Shanghai(23ZR1428200)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning for financial support.
文摘Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities.As the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.
基金Project supported by the Fundamental Research Funds for the Central Universities(No.2572014BB08)the National Natural Science Foundation of China(Nos.51405075,61304182,71371141,and 71001080)
文摘Facility location allocation(FLA) is one of the important issues in the logistics and transportation fields. In practice, since customer demands, allocations, and even locations of customers and facilities are usually changing, the FLA problem features uncertainty. To account for this uncertainty, some researchers have addressed the fuzzy profit and cost issues of FLA. However, a decision-maker needs to reach a specific profit, minimizing the cost to target customers. To handle this issue it is essential to propose an effective fuzzy cost-profit tradeoff approach of FLA. Moreover, some regional constraints can greatly influence FLA. By taking a vehicle inspection station as a typical automotive service enterprise example, and combined with the credibility measure of fuzzy set theory, this work presents new fuzzy cost-profit tradeoff FLA models with regional constraints. A hybrid algorithm integrating fuzzy simulation and genetic algorithms(GA) is proposed to solve the proposed models. Some numerical examples are given to illustrate the proposed models and the effectiveness of the proposed algorithm.
基金supported by the National Natural Science Foundation of China(Nos.21772083 and 21822104)the Shenzhen Science and Technology Innovation Committee(KQJSCX2017072816252838 and JCYJ20180504165810828)+1 种基金Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)the Shenzhen Nobel Prize Scientists Laboratory Project(C17213101)。
文摘Enantioselective recognition in water remains an ongoing challenge in supramolecular chemistry but is routine in nature.Herein,we report the first enantiopure pair of biomimetic macrocyclic receptors with hydrogen bonding donors in their deep hydrophobic cavities.The chiral naphthotubes can be efficiently synthesized through a chirality-directed macrocyclization strategy and are able to discriminate the enantiomers of neutral chiral molecules in water.Density functional theory calculations reveal that the“three-point contact”model effectively explains their enantioselectivity.The differential noncovalent interactions inside the hydrophobic cavity are responsible for the enantioselective recognition.Moreover,these chiral naphthotubes are both fluorescent and circular dichroism(CD)-active.In CD spectroscopy,they have been demonstrated to have the ability to detect nonchromophoric,achiral molecules in water.And,the use of fluorescence spectroscopy has aided in the determination of the enantiomeric excess(ee)values of chiral molecules.The results and conclusions obtained with these chiral biomimetic receptors can be used to better understand enantioselective recognition in biological systems.
基金supported by the National Natu-ral Science Foundation of China(No.21202020 and J1103303)the Doctoral Fund of Ministry of Education of China(20123514120002)the Science&Tech-nical Development Foundation of Fuzhou University(Nos.2012-XQ-10 and 2013-XQ-14).
文摘A facile method for the selective synthesis of pillar[6]arenes has been developed.Due to a strong electron do-nor-acceptor interaction between the electron-deficient naphthalene diimide and a precursor for the pillararene,1,4-diisobutoxy-2,5-bis(methoxymethyl)benzene,naphthalene diimide has been demonstrated to act as a template for selective synthesis of pillar[6]arene in a modest yield(30%).
