Lanthanide chelates and copper-free‘click’chemistry have important uses for targeted molecular imaging and therapeutic strategies.Herein,we report the complexation of lanthanides to a tetrazine-functionalised DO3A m...Lanthanide chelates and copper-free‘click’chemistry have important uses for targeted molecular imaging and therapeutic strategies.Herein,we report the complexation of lanthanides to a tetrazine-functionalised DO3A macrocyclic chelator and the tetrazine-TCO ligation between the lanthanide(DO3A-tetrazine)complexes and a TCO-PEG_(4)-functionalised rhodamine as a model agent.The luminescent and magnetic properties of the resultant dual-modal conjugates are described.The tetrazine moiety was found to sensitise terbium luminescence,resulting in a‘turn-off’effect upon its transformation to the dihydropyridazine linker,with the rhodamine moiety then dominating the fluorescence emissions.The T_(1) relaxivities of Gd(DO3A-tetrazine)and Gd(DO3A-PEG_(4)-rhodamine)were found to be similar to[Gd(DOTA)]−(Dotarem®).As a proof-of-concept in vivo test,the click conjugates were delivered to mice brains using the combination of focused ultrasound and microbubbles,with neuron uptake of the probes observed.展开更多
Epoxides are an extremely important class of chemical intermediates in the chemical industry due to the versatility of epoxides in preparing many fine and specialty chemicals.However,designing more active and selectiv...Epoxides are an extremely important class of chemical intermediates in the chemical industry due to the versatility of epoxides in preparing many fine and specialty chemicals.However,designing more active and selective heterogeneous catalysts in epoxidation is still a priority and a challenge.In this work,we demonstrate the synthesis of two new Ag/polyoxometalate-based coordination polymers(Ag_(8)(mttz)_(4)(H_(2)O)[PWVWVI 11O_(4)0]·H_(2)O(1)and Ag_(8)(mttz)4(H_(2)O)[PMo^(V)Mo^(VI)11O_(4)0](2),mttz=5-methylthio-2Htetrazole)that are highly active for the selective oxidation of cis-cyclooctene to epoxycyclooctane under mild conditions(solvent-free,atmospheric pressure,70℃with H_(2)O_(2)as the oxidant under visible light).It is worth noting that compound 1 possesses abundant exposed active edge sites of Ag,resulting in the catalytic performance achieved in the selective oxidation of cis-cyclooctene to epoxycyclooctane being superior to its components(metal,polyoxometalates and ligand)and compound 2 with the conversion/selectivity to epoxycyclooctane of 70.15/99.68%,respectively.The excellent photocatalytic activity of compound 1 should be attributed to the synergy of the components after coordination polymerization and its structure with exposed active edge sites of Ag.展开更多
The highly efficient and highly selective photocatalytic oxidation of alkenes under mild conditions is an important objective in chemical production and catalysis chemistry in the 21st century.Although there has been ...The highly efficient and highly selective photocatalytic oxidation of alkenes under mild conditions is an important objective in chemical production and catalysis chemistry in the 21st century.Although there has been extensive investigation into new photocatalysts for cis-cyclooctene oxidation,the problems of low conversion and poor selectivity still exist in current production processes.Herein,we demonstrate that ZnS-N/C nanocomposites synthesized by a facile one-step conversion from Zn-based chiral metal–organic frameworks as a photocatalyst exhibit excellent photocatalytic activity for the selective oxidation of cis-cyclooctene under visible light with air as an oxidant at 80℃(conversion based on cis-cyclooctene is about 66.32%and the selectivity for epoxycyclooctane is about 93.42%).The excellent photocatalytic activity of the ZnS-N/C nanocomposites should be attributed to the synergistic effect between the ZnS and N-doping carbon.展开更多
In most Suzuki–Miyaura carbon-carbon cross-coupling reactions,the borabicyclo[3.3.1]nonane scaffold(9-BBN)only serves as an auxiliary facilitating the transmetalation step and thus is transformed into by-products.The...In most Suzuki–Miyaura carbon-carbon cross-coupling reactions,the borabicyclo[3.3.1]nonane scaffold(9-BBN)only serves as an auxiliary facilitating the transmetalation step and thus is transformed into by-products.There are rare examples where the 9-BBN derivatives serve as the potentially diverse C8 building blocks in cross-coupling reactions.Herein,we report a cobalt-catalyzed migratory carboncarbon cross-coupling reaction of the in situ formed 9-BBN ate complexes to afford diverse aryl-and alkyl-functionalized cyclooctenes.Preliminary mechanistic studies suggest the oxidation-induced cisbicyclo[3.3.0]oct-1-ylborane is the key intermediate in this migratory cross-coupling reaction,which promotes the development of other diverse migratory cross-coupling of borate complexes.展开更多
基金funding from the EPSRC Centre for Doctoral Training in Smart Medical Imaging(EP/S022104/1)the Department of Bioengineering,Imperial College London+4 种基金supported by funding from the EPSRC grant(EP/X01374X/1)funding from the Rosetrees Trust and the John Black Charitable Foundation(Grant No.A2200)supported by an Imperial College London President’s Scholarship.S.V.M.acknowledges funding from her Imperial College Research Fellowship.M.F.L.received funding from Cancer Research UK(No.190133,DRCMDP-Nov24/100005)the Rosetrees Trust and the John Black Charitable Foundation(Grant No.A2200)the Brain Tumour Charity(Grant No.QfC_2018_10387).
文摘Lanthanide chelates and copper-free‘click’chemistry have important uses for targeted molecular imaging and therapeutic strategies.Herein,we report the complexation of lanthanides to a tetrazine-functionalised DO3A macrocyclic chelator and the tetrazine-TCO ligation between the lanthanide(DO3A-tetrazine)complexes and a TCO-PEG_(4)-functionalised rhodamine as a model agent.The luminescent and magnetic properties of the resultant dual-modal conjugates are described.The tetrazine moiety was found to sensitise terbium luminescence,resulting in a‘turn-off’effect upon its transformation to the dihydropyridazine linker,with the rhodamine moiety then dominating the fluorescence emissions.The T_(1) relaxivities of Gd(DO3A-tetrazine)and Gd(DO3A-PEG_(4)-rhodamine)were found to be similar to[Gd(DOTA)]−(Dotarem®).As a proof-of-concept in vivo test,the click conjugates were delivered to mice brains using the combination of focused ultrasound and microbubbles,with neuron uptake of the probes observed.
基金supported by the Collaborative Innovation Center of Suzhou Nano Science and Technology,the National Natural Science Foundation of China(51725204,51572179,21471106,21771132,21501126)China Petrochemical Corporation(SINOPEC,417004-1)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20161216)the 111 Project and a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Epoxides are an extremely important class of chemical intermediates in the chemical industry due to the versatility of epoxides in preparing many fine and specialty chemicals.However,designing more active and selective heterogeneous catalysts in epoxidation is still a priority and a challenge.In this work,we demonstrate the synthesis of two new Ag/polyoxometalate-based coordination polymers(Ag_(8)(mttz)_(4)(H_(2)O)[PWVWVI 11O_(4)0]·H_(2)O(1)and Ag_(8)(mttz)4(H_(2)O)[PMo^(V)Mo^(VI)11O_(4)0](2),mttz=5-methylthio-2Htetrazole)that are highly active for the selective oxidation of cis-cyclooctene to epoxycyclooctane under mild conditions(solvent-free,atmospheric pressure,70℃with H_(2)O_(2)as the oxidant under visible light).It is worth noting that compound 1 possesses abundant exposed active edge sites of Ag,resulting in the catalytic performance achieved in the selective oxidation of cis-cyclooctene to epoxycyclooctane being superior to its components(metal,polyoxometalates and ligand)and compound 2 with the conversion/selectivity to epoxycyclooctane of 70.15/99.68%,respectively.The excellent photocatalytic activity of compound 1 should be attributed to the synergy of the components after coordination polymerization and its structure with exposed active edge sites of Ag.
基金supported by the Collaborative Innovation Center of Suzhou Nano Science and Technology,China Petrochemical Corporation(SINOPEC,417004-1)the National Natural Science Foundation of China(51725204,21771132,51422207,51572179,21471106,21501126)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20161216)funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘The highly efficient and highly selective photocatalytic oxidation of alkenes under mild conditions is an important objective in chemical production and catalysis chemistry in the 21st century.Although there has been extensive investigation into new photocatalysts for cis-cyclooctene oxidation,the problems of low conversion and poor selectivity still exist in current production processes.Herein,we demonstrate that ZnS-N/C nanocomposites synthesized by a facile one-step conversion from Zn-based chiral metal–organic frameworks as a photocatalyst exhibit excellent photocatalytic activity for the selective oxidation of cis-cyclooctene under visible light with air as an oxidant at 80℃(conversion based on cis-cyclooctene is about 66.32%and the selectivity for epoxycyclooctane is about 93.42%).The excellent photocatalytic activity of the ZnS-N/C nanocomposites should be attributed to the synergistic effect between the ZnS and N-doping carbon.
基金supported by the National Natural Science Foundation of China(No.22171046)the Hundred-Talent Project of Fujian(No.50021113)Fuzhou University(No.0480-00489503)。
文摘In most Suzuki–Miyaura carbon-carbon cross-coupling reactions,the borabicyclo[3.3.1]nonane scaffold(9-BBN)only serves as an auxiliary facilitating the transmetalation step and thus is transformed into by-products.There are rare examples where the 9-BBN derivatives serve as the potentially diverse C8 building blocks in cross-coupling reactions.Herein,we report a cobalt-catalyzed migratory carboncarbon cross-coupling reaction of the in situ formed 9-BBN ate complexes to afford diverse aryl-and alkyl-functionalized cyclooctenes.Preliminary mechanistic studies suggest the oxidation-induced cisbicyclo[3.3.0]oct-1-ylborane is the key intermediate in this migratory cross-coupling reaction,which promotes the development of other diverse migratory cross-coupling of borate complexes.
