A new catalytic decarboxylative cyanation and thiocyanation via a synergistic Na I/Cu catalysis is developed.The photoexcited electron donor-acceptor complex by assembly of Na I,R3P,and N-acyloxy-phthalimide ester(NHP...A new catalytic decarboxylative cyanation and thiocyanation via a synergistic Na I/Cu catalysis is developed.The photoexcited electron donor-acceptor complex by assembly of Na I,R3P,and N-acyloxy-phthalimide ester(NHPI ester)triggers the generation of alkyl radical species,which then engages in Cu-catalyzed radical coupling process.Key to success of this dual catalytic transformation is the reliable charge transfer between I·and Cu(I).This dual catalytic platform can eliminate the use of expensive iridium-based photocatalyst or synthetically elaborate organic dyes.A series of primary,secondary,and tertiary alkyl nitriles and thiocyanates are easily synthesized.Moreover,an asymmetric decarboxylative cyanation by applying a chiral Cu catalyst is also developed to afford chiral nitriles in high enantioselectivity.The mechanistic details and the origin of the high enantioselectivity are further investigated by the mechanistic experiments and the density functional theory calculations.展开更多
Comprehensive Summary A novel transient SET mediator approach has been developed for the photoinduced radical-radical cross coupling reaction.Using the in-situ generated thianthrene radical cation as the transient SET...Comprehensive Summary A novel transient SET mediator approach has been developed for the photoinduced radical-radical cross coupling reaction.Using the in-situ generated thianthrene radical cation as the transient SET mediator,the thiocyanation and selenocyanation of aryl thianthrenium salts have been realized under the mild conditions without the need for photocatalyst or single electron donor.In comparison with the photocatalyst enabled process,the protocol features mild conditions,simple manipulation,a broad substrate scope,excellent functional group and heterocycle tolerance.Due to the feasible accessibility of aryl thianthrenium salts,this method has also been applied in the efficient synthesis of a bioactive molecule,and the late-stage functionalization of complex arenes.展开更多
A simple and efficient protocol for the electrophilic thiocyanation of indoles and aromatic amines with thiourea/NCS/NH4SCN system has been developed. The major features of the present procedure are the mild condition...A simple and efficient protocol for the electrophilic thiocyanation of indoles and aromatic amines with thiourea/NCS/NH4SCN system has been developed. The major features of the present procedure are the mild conditions, good yields, short reaction times, and the use of inexpensive and readily available organocatalyst. Moreover, N-chlorosueeinimide （NCS） was found to be indispensable, and thiourea could greatly promote the reaction.展开更多
A convenient and efficient phosphine-free procedure for the one-pot conversion of primary,secondary and tertiary alcohols into the corresponding alkyl thiocyanates or alkyl isothiocyanates is described using trichloro...A convenient and efficient phosphine-free procedure for the one-pot conversion of primary,secondary and tertiary alcohols into the corresponding alkyl thiocyanates or alkyl isothiocyanates is described using trichloroisocyanuric acid/NHUSCN.展开更多
3-Thiocyanated chromones was conveniently synthesized from alkynyl aryl ketones using commercially available,inexpensive trichloroisocyanuric acid(TCCA)as oxidant and NH_(4)SCN as thiocyanato(SCN)source.This metalfree...3-Thiocyanated chromones was conveniently synthesized from alkynyl aryl ketones using commercially available,inexpensive trichloroisocyanuric acid(TCCA)as oxidant and NH_(4)SCN as thiocyanato(SCN)source.This metalfree approach is postulated to first in situ generate thiocyanogen chloride(Cl-SCN)from the reaction of TCCA and NH_(4)SCN,followed by a rare efficient electrophilic thiocyano oxyfunctionalization of alkynes enabled by the reactive electrophilic species generated thereof.展开更多
Instead of Br_2 and Cl_2,NBS and NCS are applicable to the thiocyanation of o-nitroaniline and carbendazim.The results show that NBS and NCS are superior to Br_2 and Cl_2 due to their easier operation.
The reaction of pyridin-2(1H)·ones with PhlCl_(2) and NH_(4)SCN enables an efficient regioselective thiocyanation,leading to the synthesis of the biologically interesting C5 thiocyanated 2-pyridones in good to hi...The reaction of pyridin-2(1H)·ones with PhlCl_(2) and NH_(4)SCN enables an efficient regioselective thiocyanation,leading to the synthesis of the biologically interesting C5 thiocyanated 2-pyridones in good to high yields.The mechanistic pathway of this metal-free approach is postulated to involve the formation of the reactive thiocyanogen chloride from the reaction of PhlCl_(2) and NH4SCN followed with the regioselective electrophilic thiocyanation of the pyridin-2(1H)-one ring.展开更多
The rapid growth of using C–H bond as cross-coupling partners is reshaping the landscape of organic synthesis.C(sp3)–H functionalization via hydrogen atom transfer(HAT)represents the most compelling strategy in this...The rapid growth of using C–H bond as cross-coupling partners is reshaping the landscape of organic synthesis.C(sp3)–H functionalization via hydrogen atom transfer(HAT)represents the most compelling strategy in this avenue.Here,we demonstrate an efficient method for benzylic C–H bond thiocyanation via copper-catalyzed radical relay.The reaction exhibits broad substrate scope and exquisite benzylic selectivity with C–H substrates as limiting reagents.In addition,the benzyl thiocyanates are readily converted to other pharmaceutically important motifs,including isothiocyanate,thiourea,and others,highlighting the broad utility of this method.展开更多
Main observation and conclusion The electrochemical thiocyanation/cyclization of aldehyde hydrazones was developed under external oxidant-free and catalyst-free conditions.In contrast to previous thiocyanation,this el...Main observation and conclusion The electrochemical thiocyanation/cyclization of aldehyde hydrazones was developed under external oxidant-free and catalyst-free conditions.In contrast to previous thiocyanation,this electrosynthetic approach enabled a cascade C-H thiocyanation/cyclization through a mild,direct electrolysis manner in an undivided cell without the additive of halogens and stoichiometric oxidants.In this protocol,commercially available and inexpensive sodium thiocyanate was used,which played a dual role as a thiocyanation reagent and electrolyte.This strategy provides expedient access to functionalized sulfur-containing triazolium inner salts with ample scope and diverse functional group tolerance.Based on the findings of mechanistic studies,a reaction mechanism was proposed.展开更多
Achieving highly regioselective synthesis in organic chemistry is challenging due to the uncontrollable orientation between reacting partners.External electric fields(EEFs)can influence the reactivity and selectivity ...Achieving highly regioselective synthesis in organic chemistry is challenging due to the uncontrollable orientation between reacting partners.External electric fields(EEFs)can influence the reactivity and selectivity of the substrate by causing directional adsorption.However,scalable and efficient techniques for using EEFs as“smart catalysts”have been lacking,hindering their application.In this study,we present a novel method for modifying the regioselectivity of quinoxaline-2(1H)-ones by functionalizing their C7-position using the electric double layer(EDL)theory.This approach led to moderate to good yields of the corresponding C7-thiocyanation products.DFT calculations and control experiments demonstrated that EEFs could reverse the regioselectivity of quinoxaline-2(1H)-ones,allowing the C7-thiocyanation to proceed via a radical reaction mechanism.Additionally,the resulting 7-thiocyano-1-methylquinoxaline-2(1H)-ones exhibited promising AIE properties.Our work showcases a promising strategy for achieving highly regioselective functionalization by aligning the electric field with the desired reaction/bond axis.展开更多
基金supported by the National Natural Science Foundation of China(22201087)the National Key R&D Program of China(2022YFA1503200)Guangdong Basic and Applied Basic Research Foundation(2022A1515012507)。
文摘A new catalytic decarboxylative cyanation and thiocyanation via a synergistic Na I/Cu catalysis is developed.The photoexcited electron donor-acceptor complex by assembly of Na I,R3P,and N-acyloxy-phthalimide ester(NHPI ester)triggers the generation of alkyl radical species,which then engages in Cu-catalyzed radical coupling process.Key to success of this dual catalytic transformation is the reliable charge transfer between I·and Cu(I).This dual catalytic platform can eliminate the use of expensive iridium-based photocatalyst or synthetically elaborate organic dyes.A series of primary,secondary,and tertiary alkyl nitriles and thiocyanates are easily synthesized.Moreover,an asymmetric decarboxylative cyanation by applying a chiral Cu catalyst is also developed to afford chiral nitriles in high enantioselectivity.The mechanistic details and the origin of the high enantioselectivity are further investigated by the mechanistic experiments and the density functional theory calculations.
基金We gratefully acknowledge National Natural Science Foundation of China(22101291,22171277,21821002)National Key R&D Program of China(2021YFA1500200)+1 种基金Shanghai Rising-Star Program(20QA1411400)Shanghai Institute of Organic Chemistry,and State Key Laboratory of Organometallic Chemistry for finan cial support.
文摘Comprehensive Summary A novel transient SET mediator approach has been developed for the photoinduced radical-radical cross coupling reaction.Using the in-situ generated thianthrene radical cation as the transient SET mediator,the thiocyanation and selenocyanation of aryl thianthrenium salts have been realized under the mild conditions without the need for photocatalyst or single electron donor.In comparison with the photocatalyst enabled process,the protocol features mild conditions,simple manipulation,a broad substrate scope,excellent functional group and heterocycle tolerance.Due to the feasible accessibility of aryl thianthrenium salts,this method has also been applied in the efficient synthesis of a bioactive molecule,and the late-stage functionalization of complex arenes.
基金This project was financially supported by the National Natural Science Foundation of China （No. 21302014）.
文摘A simple and efficient protocol for the electrophilic thiocyanation of indoles and aromatic amines with thiourea/NCS/NH4SCN system has been developed. The major features of the present procedure are the mild conditions, good yields, short reaction times, and the use of inexpensive and readily available organocatalyst. Moreover, N-chlorosueeinimide （NCS） was found to be indispensable, and thiourea could greatly promote the reaction.
基金Shahid Chamran University Research Council,Ahvaz,for financial support of this investigation
文摘A convenient and efficient phosphine-free procedure for the one-pot conversion of primary,secondary and tertiary alcohols into the corresponding alkyl thiocyanates or alkyl isothiocyanates is described using trichloroisocyanuric acid/NHUSCN.
基金We acknowledge the National Natural Science Foundation of China(No.22071175)for financial supportX.B.Wang thanks the financial support from the National Natural Science Foundation of China(Nos.21908018,22078174),and Qi Lu Young Scholar Start-up Foundation of Shandong University.
文摘3-Thiocyanated chromones was conveniently synthesized from alkynyl aryl ketones using commercially available,inexpensive trichloroisocyanuric acid(TCCA)as oxidant and NH_(4)SCN as thiocyanato(SCN)source.This metalfree approach is postulated to first in situ generate thiocyanogen chloride(Cl-SCN)from the reaction of TCCA and NH_(4)SCN,followed by a rare efficient electrophilic thiocyano oxyfunctionalization of alkynes enabled by the reactive electrophilic species generated thereof.
文摘Instead of Br_2 and Cl_2,NBS and NCS are applicable to the thiocyanation of o-nitroaniline and carbendazim.The results show that NBS and NCS are superior to Br_2 and Cl_2 due to their easier operation.
基金Y.Du acknowledges the National Natural Science Foundation of China(No.22071175)for financial support.
文摘The reaction of pyridin-2(1H)·ones with PhlCl_(2) and NH_(4)SCN enables an efficient regioselective thiocyanation,leading to the synthesis of the biologically interesting C5 thiocyanated 2-pyridones in good to high yields.The mechanistic pathway of this metal-free approach is postulated to involve the formation of the reactive thiocyanogen chloride from the reaction of PhlCl_(2) and NH4SCN followed with the regioselective electrophilic thiocyanation of the pyridin-2(1H)-one ring.
基金support from the National Nature Science Foundation of China(nos.21532009,91956202,21821002,21790330,and 21761142010)the Science and Technology Commission of Shanghai Municipality(nos.19590750400 and 17JC1401200)+1 种基金the strategic Priority Research Program(no.XDB20000000),the Key Research Program of Frontier Science(no.QYZDJSSW-SLH055)the International Partnership Program(no.121731KYSB20190016)of the Chinese Academy of Sciences.P.C.also thanks the Youth Innovation Promotion Association CAS(no.2018292).
文摘The rapid growth of using C–H bond as cross-coupling partners is reshaping the landscape of organic synthesis.C(sp3)–H functionalization via hydrogen atom transfer(HAT)represents the most compelling strategy in this avenue.Here,we demonstrate an efficient method for benzylic C–H bond thiocyanation via copper-catalyzed radical relay.The reaction exhibits broad substrate scope and exquisite benzylic selectivity with C–H substrates as limiting reagents.In addition,the benzyl thiocyanates are readily converted to other pharmaceutically important motifs,including isothiocyanate,thiourea,and others,highlighting the broad utility of this method.
基金Support by the National Natural Science Foundation of China(No.21901052)the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2019)+1 种基金the Guangzhou Education Bureau University Scientific Research Project(No.201831845)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010722)is most gratefully acknowledged.
文摘Main observation and conclusion The electrochemical thiocyanation/cyclization of aldehyde hydrazones was developed under external oxidant-free and catalyst-free conditions.In contrast to previous thiocyanation,this electrosynthetic approach enabled a cascade C-H thiocyanation/cyclization through a mild,direct electrolysis manner in an undivided cell without the additive of halogens and stoichiometric oxidants.In this protocol,commercially available and inexpensive sodium thiocyanate was used,which played a dual role as a thiocyanation reagent and electrolyte.This strategy provides expedient access to functionalized sulfur-containing triazolium inner salts with ample scope and diverse functional group tolerance.Based on the findings of mechanistic studies,a reaction mechanism was proposed.
基金supported by the National Natural Science Foundation of China(21172200,21302172)the Basic Research Training Project of Zhengzhou University(JC2020053021)supported by the National Research Foundation of Korea(CRI Project No.2018R1A3B1052702 for Jong Seung Kim)。
文摘Achieving highly regioselective synthesis in organic chemistry is challenging due to the uncontrollable orientation between reacting partners.External electric fields(EEFs)can influence the reactivity and selectivity of the substrate by causing directional adsorption.However,scalable and efficient techniques for using EEFs as“smart catalysts”have been lacking,hindering their application.In this study,we present a novel method for modifying the regioselectivity of quinoxaline-2(1H)-ones by functionalizing their C7-position using the electric double layer(EDL)theory.This approach led to moderate to good yields of the corresponding C7-thiocyanation products.DFT calculations and control experiments demonstrated that EEFs could reverse the regioselectivity of quinoxaline-2(1H)-ones,allowing the C7-thiocyanation to proceed via a radical reaction mechanism.Additionally,the resulting 7-thiocyano-1-methylquinoxaline-2(1H)-ones exhibited promising AIE properties.Our work showcases a promising strategy for achieving highly regioselective functionalization by aligning the electric field with the desired reaction/bond axis.
