Inexpensive and efficient Cu(Ⅰ) catalysis is reported for the synthesis of α-hydroxy ketones from propargylic alcohols, CO2, and water via tandem carboxylative cyclization and nucleophilic addition reaction. Notably...Inexpensive and efficient Cu(Ⅰ) catalysis is reported for the synthesis of α-hydroxy ketones from propargylic alcohols, CO2, and water via tandem carboxylative cyclization and nucleophilic addition reaction. Notably, hydration of propargylic alcohols can be carried out smoothly under atmospheric CO2 pressure, generating a series of α-hydroxy ketones efficiently and selectively. This strategy shows great potential for the preparation of valuable α-hydroxy ketones by using CO2 as a crucial cocatalyst under mild conditions.展开更多
The role of carbodiimide as dehydrant in the chemo‐,regio‐and stereoselective Pd(Ⅱ/0)‐catalyzed hydrocarboxylation of various alkynes with HCOOH releasing CO in situ is reported for the first time to obtainα,β‐...The role of carbodiimide as dehydrant in the chemo‐,regio‐and stereoselective Pd(Ⅱ/0)‐catalyzed hydrocarboxylation of various alkynes with HCOOH releasing CO in situ is reported for the first time to obtainα,β‐unsaturated carboxylic acids.Both symmetrical and unsymmetrical monoalkynes show good reactivity.Importantly,2,2’‐(1,4‐phenylene)diacrylic acid can also be synthesized in high yield through the dihydrocarboxylation of 1,4‐diethynylbenzene.Besides,an excellent result in gram scale experiment and TON up to 900 can be obtained,displaying the efficiency of this protocol.Notably,regulating the types and concentrations of dehydrant can control the CO generation,avoiding directly operating toxic CO and circumventing sensitivity issue to the CO amount.On the basis of the attractive features of formic acid including easy preparation through CO_(2) hydrogenation and efficient liberation of CO,this protocol using formic acid as bridging reagent between CO_(2) and CO can be perceived as an indirect utilization of CO_(2),offering an alternative method for preparing acrylic acid analogues.展开更多
Summary of main observation and conclusion Converting CO2 into value-added chemicals represents a promising way to alleviate the CO2 derived environmental issues,for which the development of catalysts with high effici...Summary of main observation and conclusion Converting CO2 into value-added chemicals represents a promising way to alleviate the CO2 derived environmental issues,for which the development of catalysts with high efficiency and recyclability is very desirable.Herein,the catalytic system by combining cobalt source and ionic liquid(IL)has been developed as the efficacious and recyclable catalyst for the carboxylative cyclization of propargylic amine and CO2 to prepare 2-oxazolinones.In this protocol,various propargylic amines were successfully transformed into the corresponding 2-oxazolinones with CoBr2 and diethylimidazolium acetate([EEIM][OAc])as the catalyst under atmospheric CO2 pressure.It is worth noting that the turnover number(TON)of this transformation can be up to 1740,presumably being attributed to the cooperative effect of the cobalt and IL.Furthermore,the existence of IL enables the catalytic system to be easily recycled to 10 times without losing its activity.展开更多
In the photoreduction of CO_(2) to CO,the competitive H2 evolution is always inevitable due to the approximate reduction potentials of H+/H2 and CO_(2)/CO,which results in poor selectivity for CO production.Herein,imi...In the photoreduction of CO_(2) to CO,the competitive H2 evolution is always inevitable due to the approximate reduction potentials of H+/H2 and CO_(2)/CO,which results in poor selectivity for CO production.Herein,imidazolium-type ionic liquid-(IL-)modified rhenium bipyridine-based porous organometallic polymers(Re-POMP-IL)were designed as efficient and selective photocatalysts for visible-light CO_(2) photoreduction to CO based on the affinity of IL with CO_(2).Photoreduction studies demonstrated that CO_(2) photoreduction promoted by Re-POMP-IL functioning as the catalyst exhibits excellent CO selectivity up to 95.5%and generate 40.1 mmol CO/g of Re-POMP-IL1.0(obtained by providing equivalent[(5,5′-divinyl-2,2′-bipyridine)Re(CO)_(3)Cl]and 3-ethyl-1-vinyl-1H-imidazol-3-ium bromide)at 12 h,outperforming that attained with the corresponding Re-POMP analogue without IL,which highlights the crucial role of IL.Notably,CO_(2) adsorption,light harvesting,and transfer of photogenerated charges as key steps for CO_(2)RR were studied by employing POMPs modified with different amounts of IL as photocatalysts,among which the CO_(2) affinity as an important factor for POMPs catalyzed CO_(2) reduction is revealed.Overall,this work provides a practical pathway to improve the CO_(2) photoreduction efficiency and CO selectivity by employing IL as a regulator.展开更多
基金supported by National Natural Science Foundation of China(21672119)China Postdoctoral Science Foundation(2018M641624)~~
文摘Inexpensive and efficient Cu(Ⅰ) catalysis is reported for the synthesis of α-hydroxy ketones from propargylic alcohols, CO2, and water via tandem carboxylative cyclization and nucleophilic addition reaction. Notably, hydration of propargylic alcohols can be carried out smoothly under atmospheric CO2 pressure, generating a series of α-hydroxy ketones efficiently and selectively. This strategy shows great potential for the preparation of valuable α-hydroxy ketones by using CO2 as a crucial cocatalyst under mild conditions.
文摘The role of carbodiimide as dehydrant in the chemo‐,regio‐and stereoselective Pd(Ⅱ/0)‐catalyzed hydrocarboxylation of various alkynes with HCOOH releasing CO in situ is reported for the first time to obtainα,β‐unsaturated carboxylic acids.Both symmetrical and unsymmetrical monoalkynes show good reactivity.Importantly,2,2’‐(1,4‐phenylene)diacrylic acid can also be synthesized in high yield through the dihydrocarboxylation of 1,4‐diethynylbenzene.Besides,an excellent result in gram scale experiment and TON up to 900 can be obtained,displaying the efficiency of this protocol.Notably,regulating the types and concentrations of dehydrant can control the CO generation,avoiding directly operating toxic CO and circumventing sensitivity issue to the CO amount.On the basis of the attractive features of formic acid including easy preparation through CO_(2) hydrogenation and efficient liberation of CO,this protocol using formic acid as bridging reagent between CO_(2) and CO can be perceived as an indirect utilization of CO_(2),offering an alternative method for preparing acrylic acid analogues.
基金This work was financially supported by National Natural Science Foundation of China(Nos.21672119,21975135)the China Postdoctoral Science Foundation(No.2018M641624).
文摘Summary of main observation and conclusion Converting CO2 into value-added chemicals represents a promising way to alleviate the CO2 derived environmental issues,for which the development of catalysts with high efficiency and recyclability is very desirable.Herein,the catalytic system by combining cobalt source and ionic liquid(IL)has been developed as the efficacious and recyclable catalyst for the carboxylative cyclization of propargylic amine and CO2 to prepare 2-oxazolinones.In this protocol,various propargylic amines were successfully transformed into the corresponding 2-oxazolinones with CoBr2 and diethylimidazolium acetate([EEIM][OAc])as the catalyst under atmospheric CO2 pressure.It is worth noting that the turnover number(TON)of this transformation can be up to 1740,presumably being attributed to the cooperative effect of the cobalt and IL.Furthermore,the existence of IL enables the catalytic system to be easily recycled to 10 times without losing its activity.
基金This work was financially supported by the National Natural Science Foundation of China(21672119,21975135)China Postdoctoral Science Foundation(2018M641624)+2 种基金National Key Research and Development Program(2016YFA0602900)the Ph.D.Candidate Research Innovation Fund of the College of Chemistry Nankai UniversityWe also appreciate the support from Prof.Tong Bu Lu,Dr.Song Guo,and Ping Wang(Tianjin University of Technology)in photoluminescence lifetime measurement.
文摘In the photoreduction of CO_(2) to CO,the competitive H2 evolution is always inevitable due to the approximate reduction potentials of H+/H2 and CO_(2)/CO,which results in poor selectivity for CO production.Herein,imidazolium-type ionic liquid-(IL-)modified rhenium bipyridine-based porous organometallic polymers(Re-POMP-IL)were designed as efficient and selective photocatalysts for visible-light CO_(2) photoreduction to CO based on the affinity of IL with CO_(2).Photoreduction studies demonstrated that CO_(2) photoreduction promoted by Re-POMP-IL functioning as the catalyst exhibits excellent CO selectivity up to 95.5%and generate 40.1 mmol CO/g of Re-POMP-IL1.0(obtained by providing equivalent[(5,5′-divinyl-2,2′-bipyridine)Re(CO)_(3)Cl]and 3-ethyl-1-vinyl-1H-imidazol-3-ium bromide)at 12 h,outperforming that attained with the corresponding Re-POMP analogue without IL,which highlights the crucial role of IL.Notably,CO_(2) adsorption,light harvesting,and transfer of photogenerated charges as key steps for CO_(2)RR were studied by employing POMPs modified with different amounts of IL as photocatalysts,among which the CO_(2) affinity as an important factor for POMPs catalyzed CO_(2) reduction is revealed.Overall,this work provides a practical pathway to improve the CO_(2) photoreduction efficiency and CO selectivity by employing IL as a regulator.
