A theoretical investigation of the reaction mechanisms for C-H and C-C bond activation processes in the reaction of Ni with cycloalkanes C,,H2. （n = 3-7） is carried out. For the Ni ＋ CnH2, （n = 3, 4） reactions, t...A theoretical investigation of the reaction mechanisms for C-H and C-C bond activation processes in the reaction of Ni with cycloalkanes C,,H2. （n = 3-7） is carried out. For the Ni ＋ CnH2, （n = 3, 4） reactions, the major and minor reaction channels involve C-C and C-H bond activations, respectively, whereas Ni atom prefers the attacking of C-H bond over the C-C bond in CnH2n （n = 5=7）. The results are in good agreement with the experimental study. In all cases, intermediates and transition states along the reaction paths of interest are characterized, It is found that both the C-H and C-C bond activation processes are proposed to proceed in a one-step manner via one transition state. The overall C-H and C-C bond activation processes are exothermic and involve low energy barriers, thus transition metal atom Ni is a good mediator for the activity of cycloalkanes CnH2n （n = 3 -7）.展开更多
Converting hydrocarbons into aldehydes in a green and environmentally benign way is of great signif-icance in fine chemistry.In this work,all-inorganic Cs_(3)Bi_(2)B_(9) perovskite nanoparticles were uniformly loaded ...Converting hydrocarbons into aldehydes in a green and environmentally benign way is of great signif-icance in fine chemistry.In this work,all-inorganic Cs_(3)Bi_(2)B_(9) perovskite nanoparticles were uniformly loaded on BiOBr nanosheets via an in-situ growth method,which can selectivity photoactivate aromatic C(sp3)-H bond of toluene to generate benzaldehyde.According to the in-situ X-ray photoelectron spec-troscopy characterization,the photogenerated electrons of BiOBr transfer to Cs_(3)Bi_(2)B_(9) enforced by the in-ternal electric field under light irradiation,resulting in S-scheme heterojunction.Furthermore,theoretical calculations indicate that toluene molecules are inclined to adsorb on the BiOBr surface,subsequently in-volving the oxidation reaction to generate benzyl radical(PhCH_(2)·)by using the energetic holes of BiOBr,while the remaining photoinduced electrons in the conduction band(CB)of Cs_(3)Bi_(2)B_(9) with powerful reduction ability reduce O2 into·O_(2)^(-),which is the vital oxidative active species working on toluene selective oxidation process.Such an unexceptionable charge carrier utilization mode and tendentious ad-sorption behavior of reactants contribute to the optimized Cs_(3)Bi_(2)B_(9)/BiOBr heterojunction with excellent photocatalytic performance,achieving a maximum of 22.5%toluene conversion and 96.2%selectivity to-wards benzaldehyde formation.This work provides a rational photocatalyst heterojunction construction protocol for the selective oxidation of saturated aromatic C-H bonds.展开更多
A metal-free,green,and sustainable functionalization of unactivated alkyl sp^(3) C—H bonds is reported using iodine(III)as a feasible dehydrogenation agent under visible light or KBr,and alkyl chlorides,bromides,alco...A metal-free,green,and sustainable functionalization of unactivated alkyl sp^(3) C—H bonds is reported using iodine(III)as a feasible dehydrogenation agent under visible light or KBr,and alkyl chlorides,bromides,alcohols,and ketones could be constructed by addition of different coupling reagents.Cheap and safe iodobenzene diacetate was used to form a radical to activate the alkyl sp^(3) C—H bond in a highly efficient manner,which can construct different alkylation products by adding corresponding coupling reagents.展开更多
3d-Metal-catalyzed tertiary C(sp^(3))–H bond activation has been a formidable challenge.Herein,a tertiary C(sp^(3))–H bond is smoothly activated by Ni–Al bimetallic catalysts for dual C–H annulation of formamides ...3d-Metal-catalyzed tertiary C(sp^(3))–H bond activation has been a formidable challenge.Herein,a tertiary C(sp^(3))–H bond is smoothly activated by Ni–Al bimetallic catalysts for dual C–H annulation of formamides with alkynes,delivering a series of δ-lactams with a quaternary carbon up to 98%yield.Various tertiary C(sp^(3))–H bonds such as noncyclic,monocyclic and bridged-ring tertiary C(sp^(3))–H bonds are all compatible with the reaction.展开更多
基金Supported by the National Natural Science Foundation of China(No.20773014 and 20933001)the Research Foundation of Education Bureau of Hebei Province(No.Z2011115)+3 种基金the 111 Project of China(No.B07012)the Natural Science Foundation of Hebei Province(No.B2012105002)the Research Foundation of Tangshan Administration of Science&Technology(121302011a)the Research Foundation of Tangshan normal college(2013A04)for their support of this work
文摘A theoretical investigation of the reaction mechanisms for C-H and C-C bond activation processes in the reaction of Ni with cycloalkanes C,,H2. （n = 3-7） is carried out. For the Ni ＋ CnH2, （n = 3, 4） reactions, the major and minor reaction channels involve C-C and C-H bond activations, respectively, whereas Ni atom prefers the attacking of C-H bond over the C-C bond in CnH2n （n = 5=7）. The results are in good agreement with the experimental study. In all cases, intermediates and transition states along the reaction paths of interest are characterized, It is found that both the C-H and C-C bond activation processes are proposed to proceed in a one-step manner via one transition state. The overall C-H and C-C bond activation processes are exothermic and involve low energy barriers, thus transition metal atom Ni is a good mediator for the activity of cycloalkanes CnH2n （n = 3 -7）.
基金National Natural Science Foundation of China(Nos.21905209,52171145,and 51973078)Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2020D01B25).
文摘Converting hydrocarbons into aldehydes in a green and environmentally benign way is of great signif-icance in fine chemistry.In this work,all-inorganic Cs_(3)Bi_(2)B_(9) perovskite nanoparticles were uniformly loaded on BiOBr nanosheets via an in-situ growth method,which can selectivity photoactivate aromatic C(sp3)-H bond of toluene to generate benzaldehyde.According to the in-situ X-ray photoelectron spec-troscopy characterization,the photogenerated electrons of BiOBr transfer to Cs_(3)Bi_(2)B_(9) enforced by the in-ternal electric field under light irradiation,resulting in S-scheme heterojunction.Furthermore,theoretical calculations indicate that toluene molecules are inclined to adsorb on the BiOBr surface,subsequently in-volving the oxidation reaction to generate benzyl radical(PhCH_(2)·)by using the energetic holes of BiOBr,while the remaining photoinduced electrons in the conduction band(CB)of Cs_(3)Bi_(2)B_(9) with powerful reduction ability reduce O2 into·O_(2)^(-),which is the vital oxidative active species working on toluene selective oxidation process.Such an unexceptionable charge carrier utilization mode and tendentious ad-sorption behavior of reactants contribute to the optimized Cs_(3)Bi_(2)B_(9)/BiOBr heterojunction with excellent photocatalytic performance,achieving a maximum of 22.5%toluene conversion and 96.2%selectivity to-wards benzaldehyde formation.This work provides a rational photocatalyst heterojunction construction protocol for the selective oxidation of saturated aromatic C-H bonds.
基金supported the Natural Science Foundation of Higher Education Institutions in Anhui Province(2022AH030133,2022AH051340)National Natural Science Foundation of China(22231003,22271008)+6 种基金Shenzhen Science and Technology Program(Grant No.KQTD20190929174023858)Shenzhen Science and Technology Innovation Committee(GXWD20201231165807007-20200812100115001)Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions(2023SHIBS0004)Horizontal Cooperation Project of Fuyang Municipal Government(SXHZ202201)Key Projects of the Support Program for Outstanding Young Talents in Anhui Province Colleges and Universities(gxyqZD2020030)Yifan Pharmaceutical Co.,Ltd.(HX2019033)Innovative Drug Design&Development Collaborative Team(TDYY2021009).
文摘A metal-free,green,and sustainable functionalization of unactivated alkyl sp^(3) C—H bonds is reported using iodine(III)as a feasible dehydrogenation agent under visible light or KBr,and alkyl chlorides,bromides,alcohols,and ketones could be constructed by addition of different coupling reagents.Cheap and safe iodobenzene diacetate was used to form a radical to activate the alkyl sp^(3) C—H bond in a highly efficient manner,which can construct different alkylation products by adding corresponding coupling reagents.
基金the National Key R&D Program of China(grant no.2022YFA1504300)the National Natural Science Foundation of China(grant nos.22188101 and 22325103)+1 种基金the Haihe Laboratory of Sustainable Chemical Transformations and“Frontiers Science Center for New Organic Matter,”Nankai University(grant no.63181206)the Fundamental Research Funds for the Central Universities for financial support.
文摘3d-Metal-catalyzed tertiary C(sp^(3))–H bond activation has been a formidable challenge.Herein,a tertiary C(sp^(3))–H bond is smoothly activated by Ni–Al bimetallic catalysts for dual C–H annulation of formamides with alkynes,delivering a series of δ-lactams with a quaternary carbon up to 98%yield.Various tertiary C(sp^(3))–H bonds such as noncyclic,monocyclic and bridged-ring tertiary C(sp^(3))–H bonds are all compatible with the reaction.
