Cross-electrophile coupling of triazine esters with aryl bromides could be facilely accomplished by employing nickel as catalyst,magnesium as metal mediator,and lithium chloride as additive.The reactions proceeded eff...Cross-electrophile coupling of triazine esters with aryl bromides could be facilely accomplished by employing nickel as catalyst,magnesium as metal mediator,and lithium chloride as additive.The reactions proceeded efficiently in THF at room temperature through C—O bond activation to afford an array of structurally different diaryl ketones in moderate to good yields with wide functional group tolerance.Control experiments showed that nickel,magnesium,lithium chloride,and THF are all indispensable for the good performance of the coupling reaction.Preliminary mechanistic exploration indicated that in situ formed arylmagnesium reagent by the insertion of magnesium into aryl bromide might serve as the key intermediate of the cross-coupling.The method which avoids the utilization of moisture-labile and relatively difficult-to-obtain organometallics is step-economical,cost-efficient,and operationally simple,potentially serving as an attractive alternative to documented methods.展开更多
An example of iron-catalyzed cross-electrophile couplingof inert C-O bonds with alkyl bromides via aniron/B_(2)pin_(2) catalytic system has been developed.Aryl and heteroaryl carbamates can smoothly undergothis transf...An example of iron-catalyzed cross-electrophile couplingof inert C-O bonds with alkyl bromides via aniron/B_(2)pin_(2) catalytic system has been developed.Aryl and heteroaryl carbamates can smoothly undergothis transformation under mild conditions, deliveringthe alkylated products with good efficiency.This protocol exhibits good functional group compatibilityand enables the late-stage functionalizationof biorelevant compounds, thus providingexcellent opportunities for applications in medicinalchemistry. Control experiments and computationalstudies reveal that a high spin Fe(I/II/III) catalyticmechanism might be involved in this reactionthrough single electron transfer to activate alkylbromides, oxidative addition of aryl carbamates, andreductive elimination to form Csp^(2)-Csp^(3) bonds.展开更多
We report a Ni-catalyzed three-component cross-electrophile coupling of alkynes with alkenyl halides and fluoroalkyl halides to generate fluoroalkyl-incorporated 1,3-dienes.This mild and operationally simple protocol ...We report a Ni-catalyzed three-component cross-electrophile coupling of alkynes with alkenyl halides and fluoroalkyl halides to generate fluoroalkyl-incorporated 1,3-dienes.This mild and operationally simple protocol is distinguished by its broad substrate scope and excellent chemo-,regio-,and stereo-selectivity,offering a new and organometallic agent-free platform for the construction of fluoroalkyl-incorporated diene motifs.Preliminary mechanistic studies have been conducted to probe the potential reaction pathway.展开更多
A new protocol for the NiC12-catalyzed cross-electrophile coupling of aryl bromides with pyrimidin-2-yl tosyl- ates to give the corresponding C2-arylation pyrimidine derivatives has been developed. This study provides...A new protocol for the NiC12-catalyzed cross-electrophile coupling of aryl bromides with pyrimidin-2-yl tosyl- ates to give the corresponding C2-arylation pyrimidine derivatives has been developed. This study provides an improvement over previous methods by using pyrimidin-2-yl tosylates instead of halides as coupling partners that are stable and easily available.展开更多
Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon bonds.Herein,we report a general method,cobalt-catalyzed reductive alkynylation,to construct C(sp...Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon bonds.Herein,we report a general method,cobalt-catalyzed reductive alkynylation,to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2))bonds.This presented reaction has a broad substrate scope,enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl(pseudo)halides.This presented reaction is conducted under mild conditions,tolerating many functional groups,thus suitable for the modification and synthesis of biologically active molecules.展开更多
Reported herein is the design of a new catalytic paradigm by synergistically combining sequential paired electrosynthesis with halogen-bonding(XB)activation for the cyclization of organochlorides with olefins.This dua...Reported herein is the design of a new catalytic paradigm by synergistically combining sequential paired electrosynthesis with halogen-bonding(XB)activation for the cyclization of organochlorides with olefins.This dual activation strategy enables rapid access to densely functionalized 2-alkylidene-tetrahydrofurans with exclusive Z-selectivities,which are challenging to be synthesized by other methods.4,4′-Di-tert-butyl-2,2′-bipyridine(dtbbpy)showed an unprecedented reactivity as a XB acceptor to activate C-Cl bond by shifting its reduction potential positively by 220 m V.Distinctly different from previous electroreductions of C-Cl bonds relying upon high electrode potentials or matched redox properties between mediators and organochlorides,the XB activator employed herein has no limit on the abovementioned redox property matching but can lower the applied electrode potentials.The decreased operating potential allows broad functional group tolerance,which was highlighted by the late-stage functionalization of 11 examples of drugs and natural products-derived alkenes.展开更多
In this paper,we developed an electrophilic ring-opening reaction,which is beyond the strained small ring system.Under reductive nickel catalysis,ring-opening of diverse benzofurans via endocyclic inert carbon–oxygen...In this paper,we developed an electrophilic ring-opening reaction,which is beyond the strained small ring system.Under reductive nickel catalysis,ring-opening of diverse benzofurans via endocyclic inert carbon–oxygen bond cleavage can be achieved with an array of inactivated secondary and tertiary alkyl halides as coupling partners,allowing for the preparation of a series of(E)-o-alkenylphenols with excellent E/Z-selectivity and high functional tolerance.The utility of this method was further demonstrated through derivatizations of the ring-opening products using the o-hydroxyl group as a functional handle,providing various organic compounds in good to high efficiency.展开更多
基金the financial support from Nanjing Tech University(Start-up Grant Nos.39837118 and 39837146)National Natural Science Foundation of China(22271062,22001121,and 22171137)+1 种基金Natural Science Foundation of Jiangsu Province(BK20180690)X.-Q.Chu is grateful for the financial support from the program of China Scholarship Council(No.201908320190).
文摘Cross-electrophile coupling of triazine esters with aryl bromides could be facilely accomplished by employing nickel as catalyst,magnesium as metal mediator,and lithium chloride as additive.The reactions proceeded efficiently in THF at room temperature through C—O bond activation to afford an array of structurally different diaryl ketones in moderate to good yields with wide functional group tolerance.Control experiments showed that nickel,magnesium,lithium chloride,and THF are all indispensable for the good performance of the coupling reaction.Preliminary mechanistic exploration indicated that in situ formed arylmagnesium reagent by the insertion of magnesium into aryl bromide might serve as the key intermediate of the cross-coupling.The method which avoids the utilization of moisture-labile and relatively difficult-to-obtain organometallics is step-economical,cost-efficient,and operationally simple,potentially serving as an attractive alternative to documented methods.
基金We thank the National Key Research and Development Program of China(grant no.2021YFA1500100)National Natural Science Foundation of China(grant nos.92156017 and 21890722)+3 种基金Natural Science Foundation of Sichuan(grant no.2021YJ0413)the Natural Science Foundation of Tianjin Municipality(grant no.19JCJQJC62300)Chongqing Postdoctoral Science Foundation(grant no.cstc2020jcyj-bshX0052)Affiliated Hospital of North Sichuan Medical College(grant no.2022JB001)for financial support.
文摘An example of iron-catalyzed cross-electrophile couplingof inert C-O bonds with alkyl bromides via aniron/B_(2)pin_(2) catalytic system has been developed.Aryl and heteroaryl carbamates can smoothly undergothis transformation under mild conditions, deliveringthe alkylated products with good efficiency.This protocol exhibits good functional group compatibilityand enables the late-stage functionalizationof biorelevant compounds, thus providingexcellent opportunities for applications in medicinalchemistry. Control experiments and computationalstudies reveal that a high spin Fe(I/II/III) catalyticmechanism might be involved in this reactionthrough single electron transfer to activate alkylbromides, oxidative addition of aryl carbamates, andreductive elimination to form Csp^(2)-Csp^(3) bonds.
基金financial support provided by the National Natural Science Foundation of China(Nos.21991123,21971036,21901036)the Shanghai Rising-Star Program(No.20QA1400200)。
文摘We report a Ni-catalyzed three-component cross-electrophile coupling of alkynes with alkenyl halides and fluoroalkyl halides to generate fluoroalkyl-incorporated 1,3-dienes.This mild and operationally simple protocol is distinguished by its broad substrate scope and excellent chemo-,regio-,and stereo-selectivity,offering a new and organometallic agent-free platform for the construction of fluoroalkyl-incorporated diene motifs.Preliminary mechanistic studies have been conducted to probe the potential reaction pathway.
基金We are thankful for the financial support from the National Natural Science Foundation of China (Nos. 21362032, 21362031 and 21562036) and Northwest Normal University (No. NWNU-LKQN- 15-1 ).
文摘A new protocol for the NiC12-catalyzed cross-electrophile coupling of aryl bromides with pyrimidin-2-yl tosyl- ates to give the corresponding C2-arylation pyrimidine derivatives has been developed. This study provides an improvement over previous methods by using pyrimidin-2-yl tosylates instead of halides as coupling partners that are stable and easily available.
基金the National Natural Science Foundation of China(Nos.22371273,22293011 and T2341001)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2023476)the National Science Foundation of Anhui Province(No.2208085J26)。
文摘Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon bonds.Herein,we report a general method,cobalt-catalyzed reductive alkynylation,to construct C(sp)-C(sp^(3))and C(sp)-C(sp^(2))bonds.This presented reaction has a broad substrate scope,enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl(pseudo)halides.This presented reaction is conducted under mild conditions,tolerating many functional groups,thus suitable for the modification and synthesis of biologically active molecules.
基金supported by the National Natural Science Foundation of China(21871019,22171015)Beijing Municipal Education Committee Project(KZ202110005003,KM202110005006)Beijing Natural Science Foundation(2222003)。
文摘Reported herein is the design of a new catalytic paradigm by synergistically combining sequential paired electrosynthesis with halogen-bonding(XB)activation for the cyclization of organochlorides with olefins.This dual activation strategy enables rapid access to densely functionalized 2-alkylidene-tetrahydrofurans with exclusive Z-selectivities,which are challenging to be synthesized by other methods.4,4′-Di-tert-butyl-2,2′-bipyridine(dtbbpy)showed an unprecedented reactivity as a XB acceptor to activate C-Cl bond by shifting its reduction potential positively by 220 m V.Distinctly different from previous electroreductions of C-Cl bonds relying upon high electrode potentials or matched redox properties between mediators and organochlorides,the XB activator employed herein has no limit on the abovementioned redox property matching but can lower the applied electrode potentials.The decreased operating potential allows broad functional group tolerance,which was highlighted by the late-stage functionalization of 11 examples of drugs and natural products-derived alkenes.
基金supported by National Natural Science Foundation of China(grant no.21772183)the Fundamental Research Funds for the Central Universities(grant no.WK2060190086)“1000-Youth Talents Plan”start-up funding as well as the University of Science and Technology of China.
文摘In this paper,we developed an electrophilic ring-opening reaction,which is beyond the strained small ring system.Under reductive nickel catalysis,ring-opening of diverse benzofurans via endocyclic inert carbon–oxygen bond cleavage can be achieved with an array of inactivated secondary and tertiary alkyl halides as coupling partners,allowing for the preparation of a series of(E)-o-alkenylphenols with excellent E/Z-selectivity and high functional tolerance.The utility of this method was further demonstrated through derivatizations of the ring-opening products using the o-hydroxyl group as a functional handle,providing various organic compounds in good to high efficiency.