The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-di...The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.展开更多
A sacrificial reductant-free copper-catalyzed benzylic C-H alkoxylation with N-Fluorobenzenesulfonimide(NFSI)was reported.Mechanistic studies suggested a novel pathway for the generation of active CuI species from Cu(...A sacrificial reductant-free copper-catalyzed benzylic C-H alkoxylation with N-Fluorobenzenesulfonimide(NFSI)was reported.Mechanistic studies suggested a novel pathway for the generation of active CuI species from Cu(OAc)2,NFSI and MeOH.A proper loading amount of copper catalyst was found to balance the reaction rates of benzylic C-H alkoxylation and overoxidation of benzyl ether to exhibit the best performance.展开更多
A palladium catalyzed ortho-alkoxylation of aryl C-H bond was accomplished with primary and secondary alcohols as alkoxylation reagents and with triazole as new directing group.This transformation has a good functiona...A palladium catalyzed ortho-alkoxylation of aryl C-H bond was accomplished with primary and secondary alcohols as alkoxylation reagents and with triazole as new directing group.This transformation has a good functional group tolerance and is not sensitive to moisture and air.展开更多
Under iodine-catalyzed and visible light-irradiated aerobic conditions, selenoalkoxylation of olefins with diselenides and alcohols can be efficiently achieved to afford the useful α-alkoxyl selenides in the presence...Under iodine-catalyzed and visible light-irradiated aerobic conditions, selenoalkoxylation of olefins with diselenides and alcohols can be efficiently achieved to afford the useful α-alkoxyl selenides in the presence of only 0.5 equiv. of H_2O_2. Controlling the sub-stoichiometric H_2O_2 amount is crucial to avoid the non-selective over-oxidation of the diselenides that leads to the ineffective hyper-valent selenium compounds. Meanwhile, under visible light irradiation, the green, safe, and low-cost air can work as a supplemental mild oxidant in the reaction to ensure selective oxidation of the diselenides, full conversion of the reactants, and ultimately good yield of the products.展开更多
A new and general synthesis of a porphyrinK(Ⅰ) with two alkoxyl linkages is described. The synthesis involves the reaction of dibromopropane with phenolic porphyrin to form ω-bromopropylporphyrin ether. This ether t...A new and general synthesis of a porphyrinK(Ⅰ) with two alkoxyl linkages is described. The synthesis involves the reaction of dibromopropane with phenolic porphyrin to form ω-bromopropylporphyrin ether. This ether then reacts with another phenolic porphyrin to give the target compounds. The properties of the target compounds were confirmed by means of elemental analysis, UV-Vis, IR, and ~ 1H NMR spectroscopies. Their spectral properties and thermal stability were also studied.展开更多
The hole transport material (HTM) plays an extremely important role to determine the power conversion efficiency (PCE) and the stability of perovskite solar cells (PSCs). Herein, we report an effective strategy to imp...The hole transport material (HTM) plays an extremely important role to determine the power conversion efficiency (PCE) and the stability of perovskite solar cells (PSCs). Herein, we report an effective strategy to improve the performance of HTMs by introducing −CF_(3) groups via the rational decorative mode. Upon direct attachment or nonconjugated alkoxyl bridging of −CF_(3) groups on the terminal diphenylamines, the resulting molecular HTMs, i.e., 2,7-BCzA4CF_(3) and 2,7-BCzA4OCCF_(3), show distinct properties. Compared with 2,7-BCzA4CF_(3), the nonconjugated alkoxyl bridging −CF_(3) group-based 2,7-BCzA4OCCF_(3) exhibits better thermal stability, hydrophobicity, and a dramatically upgraded hole mobility by 135.7-fold of magnitude to 1.71 × 10^(−4) cm^(2) V^(−1) S^(−1). The PSCs with 2,7-BCzA4OCCF_(3) as HTM exhibit an PCE of up to 20.53% and excellent long-term stability, maintaining 92.57% of their performance for 30 days in air with humidity of 30% without encapsulation. This work provides beneficial guidelines for the design of new HTMs for efficient and stable PSCs.展开更多
In controlling eutrophication phenomenon, there were conventional methods which lead to negative effects to aquatic environment. This study was aimed to investigate the usage of synthesized thiourea compounds to inhib...In controlling eutrophication phenomenon, there were conventional methods which lead to negative effects to aquatic environment. This study was aimed to investigate the usage of synthesized thiourea compounds to inhibit the growth of Oscillatoria sp. in Kenyir lake, Terengganu, Malaysia. The inhibition effects of four eco-friendly alkoxyl thiourea derivatives compounds named as N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide, N-（（4-（decyloxy）phenyl）carbamothioyl）-4-nitro benzamide, 4-chloro-N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide and N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide were examined onto the growth culture of Oscillatoria sp. These compounds were tested in 30 mL of Oscillatoria sp. cultures with different concentration of 16 μg·mL-1, 18 μg·mL-1, 20 μg·mL-1, 24 μg·mL-1 and 28 μg·mL-1respectively. The treatment flasks were supplied with an aerator for 24 hours under continuous illumination at 25 ℃. Chlorophyll-a concentration were extracted to calculate the inhibition percentage of each treatment. Overall, all these compounds showed inhibition effects towards the growth of Oscillatoria sp., with the highest inhibition of 37% by N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide at the concentration of 18μg·mL-1. The methyl group that attach to the synthesized compound may contribute to the effectiveness of the compound which act as an algae inhibitor. However, extensive studies still need to be conducted in order to investigate the mechanism on how this compound reacts with Oscillatoria sp..展开更多
Oxygen evolution reaction(OER)is a bottleneck process for many electrochemical devices due to the sluggish kinetics,for which advanced electrocatalysts should be carefully designed.Nickle-based materials have been ext...Oxygen evolution reaction(OER)is a bottleneck process for many electrochemical devices due to the sluggish kinetics,for which advanced electrocatalysts should be carefully designed.Nickle-based materials have been extensively studied to catalyze OER.However,their performances are still below the expectation and the active sites are often controversial.Herein,we have successfully modulated the electronic and surface properties of layeredβ-Ni(OH)2 by the interlayer ligand engineering,aiming to design novel efficient electrocatalysts and unveil the catalysis mechanism.By one-step solvothermal reaction,alkoxyl substitutedβ-Ni(OH)2 with variable interlayer distances is obtained,and the ethoxyl substituted one(NiEt)shows great potential for efficient OER.With the assistance of powder X-ray diffraction and crystalline structure computational simulation,the formula of alkoxyl substitutedβ-Ni(OH)2 are determined.Operando X-ray absorption spectroscopy studies combined with ex-situ analyses revealed that the critical active species of NiEt is formed via hydroxylation and subsequent de-protonation,with high valent Niδ+(3<δ≤3.66).The corresponding catalytic reaction pathway and mechanism are proposed.展开更多
With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the dono...With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the donor-acceptor complex enables metal-free inert bond functionalizations,which was published in Angew Chem Int Ed(2017,56(41):12619-12623).展开更多
文摘The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.
基金supported by USTC Research Funds of the Double First-Class Initiative(YD2060002024)Youth Innovation Promotion Association CAS(2020448)+2 种基金National Natur-al Science Foundation of China(22171254)Anhui Provincial Natural Science Foundation(2108085MB58)Start-up Research Fund from University of Science and Technology of China(KY2060000216).
文摘A sacrificial reductant-free copper-catalyzed benzylic C-H alkoxylation with N-Fluorobenzenesulfonimide(NFSI)was reported.Mechanistic studies suggested a novel pathway for the generation of active CuI species from Cu(OAc)2,NFSI and MeOH.A proper loading amount of copper catalyst was found to balance the reaction rates of benzylic C-H alkoxylation and overoxidation of benzyl ether to exhibit the best performance.
基金Support of this work by the“973”Project from the MOST of China(2015CB856600)NSFC(No.21332001)is gratefully acknowledged.
文摘A palladium catalyzed ortho-alkoxylation of aryl C-H bond was accomplished with primary and secondary alcohols as alkoxylation reagents and with triazole as new directing group.This transformation has a good functional group tolerance and is not sensitive to moisture and air.
基金supported by the National Natural Science Foundation of China(21202141,21672069)Priority Academic Program Development of Jiangsu Higher Education Institutions+1 种基金the Open Project Program of Jiangsu Key Laboratory of Zoonosis(R1509)the High Level Talent Support Project of Yangzhou University
文摘Under iodine-catalyzed and visible light-irradiated aerobic conditions, selenoalkoxylation of olefins with diselenides and alcohols can be efficiently achieved to afford the useful α-alkoxyl selenides in the presence of only 0.5 equiv. of H_2O_2. Controlling the sub-stoichiometric H_2O_2 amount is crucial to avoid the non-selective over-oxidation of the diselenides that leads to the ineffective hyper-valent selenium compounds. Meanwhile, under visible light irradiation, the green, safe, and low-cost air can work as a supplemental mild oxidant in the reaction to ensure selective oxidation of the diselenides, full conversion of the reactants, and ultimately good yield of the products.
文摘A new and general synthesis of a porphyrinK(Ⅰ) with two alkoxyl linkages is described. The synthesis involves the reaction of dibromopropane with phenolic porphyrin to form ω-bromopropylporphyrin ether. This ether then reacts with another phenolic porphyrin to give the target compounds. The properties of the target compounds were confirmed by means of elemental analysis, UV-Vis, IR, and ~ 1H NMR spectroscopies. Their spectral properties and thermal stability were also studied.
基金This work was financially supported by the National Natural Science Foundation of China(62074095)the Fundamental Research Funds for the Central Universities(GK202002001).
文摘The hole transport material (HTM) plays an extremely important role to determine the power conversion efficiency (PCE) and the stability of perovskite solar cells (PSCs). Herein, we report an effective strategy to improve the performance of HTMs by introducing −CF_(3) groups via the rational decorative mode. Upon direct attachment or nonconjugated alkoxyl bridging of −CF_(3) groups on the terminal diphenylamines, the resulting molecular HTMs, i.e., 2,7-BCzA4CF_(3) and 2,7-BCzA4OCCF_(3), show distinct properties. Compared with 2,7-BCzA4CF_(3), the nonconjugated alkoxyl bridging −CF_(3) group-based 2,7-BCzA4OCCF_(3) exhibits better thermal stability, hydrophobicity, and a dramatically upgraded hole mobility by 135.7-fold of magnitude to 1.71 × 10^(−4) cm^(2) V^(−1) S^(−1). The PSCs with 2,7-BCzA4OCCF_(3) as HTM exhibit an PCE of up to 20.53% and excellent long-term stability, maintaining 92.57% of their performance for 30 days in air with humidity of 30% without encapsulation. This work provides beneficial guidelines for the design of new HTMs for efficient and stable PSCs.
文摘In controlling eutrophication phenomenon, there were conventional methods which lead to negative effects to aquatic environment. This study was aimed to investigate the usage of synthesized thiourea compounds to inhibit the growth of Oscillatoria sp. in Kenyir lake, Terengganu, Malaysia. The inhibition effects of four eco-friendly alkoxyl thiourea derivatives compounds named as N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide, N-（（4-（decyloxy）phenyl）carbamothioyl）-4-nitro benzamide, 4-chloro-N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide and N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide were examined onto the growth culture of Oscillatoria sp. These compounds were tested in 30 mL of Oscillatoria sp. cultures with different concentration of 16 μg·mL-1, 18 μg·mL-1, 20 μg·mL-1, 24 μg·mL-1 and 28 μg·mL-1respectively. The treatment flasks were supplied with an aerator for 24 hours under continuous illumination at 25 ℃. Chlorophyll-a concentration were extracted to calculate the inhibition percentage of each treatment. Overall, all these compounds showed inhibition effects towards the growth of Oscillatoria sp., with the highest inhibition of 37% by N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide at the concentration of 18μg·mL-1. The methyl group that attach to the synthesized compound may contribute to the effectiveness of the compound which act as an algae inhibitor. However, extensive studies still need to be conducted in order to investigate the mechanism on how this compound reacts with Oscillatoria sp..
基金This work was supported by the Fundamental Research Funds for the Central Universities(531107051102)the National Natural Science Foundation of China(51402100,21825201,21573066,21805080,21902047)the Provincial Natural Science Foundation of Hunan(2016TP1009,2020JJ5045).
文摘Oxygen evolution reaction(OER)is a bottleneck process for many electrochemical devices due to the sluggish kinetics,for which advanced electrocatalysts should be carefully designed.Nickle-based materials have been extensively studied to catalyze OER.However,their performances are still below the expectation and the active sites are often controversial.Herein,we have successfully modulated the electronic and surface properties of layeredβ-Ni(OH)2 by the interlayer ligand engineering,aiming to design novel efficient electrocatalysts and unveil the catalysis mechanism.By one-step solvothermal reaction,alkoxyl substitutedβ-Ni(OH)2 with variable interlayer distances is obtained,and the ethoxyl substituted one(NiEt)shows great potential for efficient OER.With the assistance of powder X-ray diffraction and crystalline structure computational simulation,the formula of alkoxyl substitutedβ-Ni(OH)2 are determined.Operando X-ray absorption spectroscopy studies combined with ex-situ analyses revealed that the critical active species of NiEt is formed via hydroxylation and subsequent de-protonation,with high valent Niδ+(3<δ≤3.66).The corresponding catalytic reaction pathway and mechanism are proposed.
文摘With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the donor-acceptor complex enables metal-free inert bond functionalizations,which was published in Angew Chem Int Ed(2017,56(41):12619-12623).
