Hydrogen bond donors(HBDs)are a sustainable privileged class of catalysts which are broadly used for the activation of compounds in synthetic chemistry.Among them,the metal-templated HBD complexes present perspective ...Hydrogen bond donors(HBDs)are a sustainable privileged class of catalysts which are broadly used for the activation of compounds in synthetic chemistry.Among them,the metal-templated HBD complexes present perspective systems with high catalytic potential.In this respect,here we report the design of the next-generation octahedral Co_((III))complexes based on cheap commercially available 1,2-phenylenediamine and 3,5-di-tert-butyl-salicylaldehyde.It was shown that the obtained Co_((III))complex with an iodide counter-anion operates as a bifunctional one-component hydrogen bond donor/nucleophilic catalyst for the fixation of carbon dioxide with epoxides into valuable cyclic carbonates under ambient conditions(RT and 1 bar CO_(4))and solvent-and co-catalyst-free conditions.The TON and TOF values of 38 and 1.6,respectively,were achieved at a low catalyst loading(2 mol%)under ambient conditions.Furthermore,the obtained Co_((III))complex catalyzed the reaction with a diluted air/CO_(4)mixture(15 vol%of CO_(4))producing the desired cyclic carbonate in a 92%yield.A plausible catalytic cycle consistent with all experimental observations was proposed based on DFT calculations.The epoxide-opening step was found to be the rate-determining step.Besides,the influence of different additives on the catalysis was investigated and explained computationally.展开更多
基金supported by the Russian Science Foundation(RSF Grant No.20-13-00155).
文摘Hydrogen bond donors(HBDs)are a sustainable privileged class of catalysts which are broadly used for the activation of compounds in synthetic chemistry.Among them,the metal-templated HBD complexes present perspective systems with high catalytic potential.In this respect,here we report the design of the next-generation octahedral Co_((III))complexes based on cheap commercially available 1,2-phenylenediamine and 3,5-di-tert-butyl-salicylaldehyde.It was shown that the obtained Co_((III))complex with an iodide counter-anion operates as a bifunctional one-component hydrogen bond donor/nucleophilic catalyst for the fixation of carbon dioxide with epoxides into valuable cyclic carbonates under ambient conditions(RT and 1 bar CO_(4))and solvent-and co-catalyst-free conditions.The TON and TOF values of 38 and 1.6,respectively,were achieved at a low catalyst loading(2 mol%)under ambient conditions.Furthermore,the obtained Co_((III))complex catalyzed the reaction with a diluted air/CO_(4)mixture(15 vol%of CO_(4))producing the desired cyclic carbonate in a 92%yield.A plausible catalytic cycle consistent with all experimental observations was proposed based on DFT calculations.The epoxide-opening step was found to be the rate-determining step.Besides,the influence of different additives on the catalysis was investigated and explained computationally.
