Strained bridged rings bicyclo[3.2.1]octane and tricyclo[3.2.1.0^(2,7)]octane are prevalent in natural products known for their significant biological activities.However,strategies for efficiently synthesizing these c...Strained bridged rings bicyclo[3.2.1]octane and tricyclo[3.2.1.0^(2,7)]octane are prevalent in natural products known for their significant biological activities.However,strategies for efficiently synthesizing these complex frameworks from simple starting materials via de novo synthesis remain underexplored.This article presents an efficient strategy that combines phosphine catalysis and photocatalysis to execute a stepwise tandem reaction involving allenoates and α-cyano cinnamaldehydes,including[3+2]cyclization,[5+2]cyclization,acyl transfer,and decarboxylation reactions,synthesizing a series of functional bicyclo[3.2.1]octa-2,6-diene and tricyclo[3.2.1.0^(2,7)]oct-3-ene skeleton derivatives with excellent chemoselectivity demonstrated throughout the process.Meanwhile,the reaction can also be performed via a onepot,scalable phosphine/photocatalytic cascade process,efficiently yielding the bridged products which can serve as versatile intermediates for further applications.展开更多
Reliable estimation of the pore size distribution(PSD) in porous materials such as metal–organic frameworks(MOFs) and zeolitic imidazolate frameworks(ZIFs) is crucial for accurately assessing adsorption capacity and ...Reliable estimation of the pore size distribution(PSD) in porous materials such as metal–organic frameworks(MOFs) and zeolitic imidazolate frameworks(ZIFs) is crucial for accurately assessing adsorption capacity and corresponding selectivity. In this study, the so-called zeolitic imidazolate framework-7(ZIF-7) is successfully synthesized via relatively fast and convenient microwave technique. The morphology and structure of the obtained MOF were characterized by XRD, SEM and N_2 and CO_2adsorption/desorption isotherms at 77 K and0 °C respectively. Then, to determine the PSD of the fabricated MOF, carbon dioxide isotherms are experimentally measured at various temperatures up to atmospheric pressure. Afterward, the experimental CO_2 isotherms data are utilized in two recently proposed in-house algorithms of SHN1 and SHN2 to extract the true PSD of manufactured ZIF-7. The obtained results revealed that median pore diameter of the fabricated ZIF-7 is estimated around 0.404 nm and 0.370 nm by using CO_2 isotherms at 273 K and 298 K respectively. These values are in good agreement with the real pore diameter of 0.42 nm. Moreover, experimental data of water adsorption isotherms over four different MOFs, borrowed from literature, are employed to illustrate further effectiveness of the above algorithms on successful determination of the corresponding pore size distributions. All predicted PSDs are proved to be in good agreement with those obtained from independent methods such as topology and morphology studies.展开更多
基金financial support from National Natural Science Foundation of China(Nos.82374020 and 22401025)Science&Technology Department of Sichuan Province(No.2024NSFTD0023)Xinglin Scholar Research Promotion Project of Chengdu University of TCM。
文摘Strained bridged rings bicyclo[3.2.1]octane and tricyclo[3.2.1.0^(2,7)]octane are prevalent in natural products known for their significant biological activities.However,strategies for efficiently synthesizing these complex frameworks from simple starting materials via de novo synthesis remain underexplored.This article presents an efficient strategy that combines phosphine catalysis and photocatalysis to execute a stepwise tandem reaction involving allenoates and α-cyano cinnamaldehydes,including[3+2]cyclization,[5+2]cyclization,acyl transfer,and decarboxylation reactions,synthesizing a series of functional bicyclo[3.2.1]octa-2,6-diene and tricyclo[3.2.1.0^(2,7)]oct-3-ene skeleton derivatives with excellent chemoselectivity demonstrated throughout the process.Meanwhile,the reaction can also be performed via a onepot,scalable phosphine/photocatalytic cascade process,efficiently yielding the bridged products which can serve as versatile intermediates for further applications.
文摘Reliable estimation of the pore size distribution(PSD) in porous materials such as metal–organic frameworks(MOFs) and zeolitic imidazolate frameworks(ZIFs) is crucial for accurately assessing adsorption capacity and corresponding selectivity. In this study, the so-called zeolitic imidazolate framework-7(ZIF-7) is successfully synthesized via relatively fast and convenient microwave technique. The morphology and structure of the obtained MOF were characterized by XRD, SEM and N_2 and CO_2adsorption/desorption isotherms at 77 K and0 °C respectively. Then, to determine the PSD of the fabricated MOF, carbon dioxide isotherms are experimentally measured at various temperatures up to atmospheric pressure. Afterward, the experimental CO_2 isotherms data are utilized in two recently proposed in-house algorithms of SHN1 and SHN2 to extract the true PSD of manufactured ZIF-7. The obtained results revealed that median pore diameter of the fabricated ZIF-7 is estimated around 0.404 nm and 0.370 nm by using CO_2 isotherms at 273 K and 298 K respectively. These values are in good agreement with the real pore diameter of 0.42 nm. Moreover, experimental data of water adsorption isotherms over four different MOFs, borrowed from literature, are employed to illustrate further effectiveness of the above algorithms on successful determination of the corresponding pore size distributions. All predicted PSDs are proved to be in good agreement with those obtained from independent methods such as topology and morphology studies.
