Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are anticipated.In this study,a formal[3+2]method,through the reactions of an o...Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are anticipated.In this study,a formal[3+2]method,through the reactions of an osmapentalyne with benzyl carbanions,was developed.The reactions underwent a nucleophilic attack of carbanions to the Os≡C bond,followed by C—H activation to form the five-membered osmacyclopentadiene ring.Most of the reactions were carried out at room temperature,the substituents on the aromatic rings of benzyl carbanions are diverse,and the resulting products contain an Os—H bond,representing a novel type of 10C-carbolong complexes.This work provides a new convenient route to construct metallacyclopentadienes,which is expected to further promote the development of such a type of substances.展开更多
Comprehensive Summary Metallacyclopentadienes play a vital role in transition-metal mediated and catalyzed cycloaddition reactions of alkynes.Though versatile reactions of metallacyclopentadienes with alkynes have bee...Comprehensive Summary Metallacyclopentadienes play a vital role in transition-metal mediated and catalyzed cycloaddition reactions of alkynes.Though versatile reactions of metallacyclopentadienes with alkynes have been disclosed,[2+1]cycloadditions of metallacyclopentadienes and alkynes have never been discovered.In present work,we report the formal[2+1]cycloadditions of a metallacyclopentadiene unit with a broad scope of commercial alkynes,providing a facile strategy to construct tetracyclic conjugated compounds.The deuterated experiment indicates a metal vinylidene intermediate has been involved in[2+1]cycloaddition.Moreover,the electrophilic substitution reaction of the tetracyclic conjugated compound with the aid of density functional theory(DFT)calculated Fukui functions is investigated.展开更多
of main observation and conclusion Oxygen atom transfer reactions between alkynes and heteroarene N-oxides are currently mediated by transition metal,such as gold,ruthenium or rhodium,but they have never been catalyze...of main observation and conclusion Oxygen atom transfer reactions between alkynes and heteroarene N-oxides are currently mediated by transition metal,such as gold,ruthenium or rhodium,but they have never been catalyzed by osmium.Herein,we report stepwise oxidations of terminal alkynes mediated by an osmium carbolong complex,using pyridine N-oxide as the oxidant,yielding novel aldehyde-or carboxylic acid-coordinated osmapentalyne derivatives selectively.The mechanism was illustrated by density functional theory calculations,providing a new route for oxygen atom transfer between heteroarene N-oxides and alkynes.展开更多
Comprehensive Summary Starting from an organic multiyne,three steps are normally needed for the preparation of non-βphosphonium functionalized rhodaand irida-carbolong complexes.Herein,a one-pot strategy,by mixing a ...Comprehensive Summary Starting from an organic multiyne,three steps are normally needed for the preparation of non-βphosphonium functionalized rhodaand irida-carbolong complexes.Herein,a one-pot strategy,by mixing a multiyne,a nucleophile,and Rhcl(CO)(PPh_(3))_(2)/AgBF_(4)or[Ir(CH:CN)(CO)(PPh_(3))_(2)]BF_(4),was developed to achieve a series ofβfunctionalized rhoda-and irida-carbolong complexes.Theβ-substituents in these complexes can be various C-,N-and O-centered groups,dependent on the nucleophiles used.This strategy provides a new convenient route to construct carbolong complexes,which is important for the further development of carbolong chemistry.展开更多
Three-membered unsaturated rings have been widely utilized in organic synthesis due to their inherent highly strained structures.Although much research has been applied to ring-expansion reactions of such strained rin...Three-membered unsaturated rings have been widely utilized in organic synthesis due to their inherent highly strained structures.Although much research has been applied to ring-expansion reactions of such strained ring systems,pathways other than[3+2]cycloadditions have rarely been observed in their reactions with alkynes,and to date,no[3+1]cycloadditions of isolated three-membered unsaturated rings with alkynes have been reported.Here we demonstrate an unprecedented[3+1]cycloaddition in which a fused metalla-azirine is used as a template to generate a series of planar CCCCX-type(X=N,O,S)pentadentate carbolong complexes 3–6.A series of substituted alkynes was tested for further exploration of the scope and mechanism for the[3+1]cycloaddition reactions.Complexes 3–6 represent rare examples of planar pentadentate complexes that assemble fourπ-conjugated fused rings by one bridgehead atom.These novel complexes are thermally stable in air and absorb ultraviolet,visible,and near-infrared light,and thus are potentially applicable in photoelectric devices and pharmaceuticals.展开更多
基金the NSFC(Nos.22071098,21931002 and 22101123)the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)+2 种基金the Shenzhen Science and Technology Innovation Committee(No.JCYJ20200109140812302)Introduction of Major Talent Projects in Guangdong Province(No.2019CX01C079)Outstanding Talents Training Fund in Shenzhen,for their financial support.
文摘Metallacyclopentadienes are important metallacycles and regarded as intermediates in many reactions,therefore,new methods to achieve them are anticipated.In this study,a formal[3+2]method,through the reactions of an osmapentalyne with benzyl carbanions,was developed.The reactions underwent a nucleophilic attack of carbanions to the Os≡C bond,followed by C—H activation to form the five-membered osmacyclopentadiene ring.Most of the reactions were carried out at room temperature,the substituents on the aromatic rings of benzyl carbanions are diverse,and the resulting products contain an Os—H bond,representing a novel type of 10C-carbolong complexes.This work provides a new convenient route to construct metallacyclopentadienes,which is expected to further promote the development of such a type of substances.
基金the National Natural Science Foundation of China(Nos.21931002,22071098,22101115,and 22101123)the Shenzhen Science and Technology Innovation Committee(Nos.JCYJ20200109140812302 and JCYJ20210324105013035)the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)。
文摘Comprehensive Summary Metallacyclopentadienes play a vital role in transition-metal mediated and catalyzed cycloaddition reactions of alkynes.Though versatile reactions of metallacyclopentadienes with alkynes have been disclosed,[2+1]cycloadditions of metallacyclopentadienes and alkynes have never been discovered.In present work,we report the formal[2+1]cycloadditions of a metallacyclopentadiene unit with a broad scope of commercial alkynes,providing a facile strategy to construct tetracyclic conjugated compounds.The deuterated experiment indicates a metal vinylidene intermediate has been involved in[2+1]cycloaddition.Moreover,the electrophilic substitution reaction of the tetracyclic conjugated compound with the aid of density functional theory(DFT)calculated Fukui functions is investigated.
基金We gratefully acknowledge the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)NSFC(Nos.U1705254 and 21931002)for their financial support.
文摘of main observation and conclusion Oxygen atom transfer reactions between alkynes and heteroarene N-oxides are currently mediated by transition metal,such as gold,ruthenium or rhodium,but they have never been catalyzed by osmium.Herein,we report stepwise oxidations of terminal alkynes mediated by an osmium carbolong complex,using pyridine N-oxide as the oxidant,yielding novel aldehyde-or carboxylic acid-coordinated osmapentalyne derivatives selectively.The mechanism was illustrated by density functional theory calculations,providing a new route for oxygen atom transfer between heteroarene N-oxides and alkynes.
基金We gratefully acknowledge the NSFC(Nos.22071098,21871068,22101123 and 22101115)the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)the Shenzhen Science and Technology Innovation Committee(Nos.JCYJ20200109140812302 and JCYJ20210324105013035),for their financial support.
文摘Comprehensive Summary Starting from an organic multiyne,three steps are normally needed for the preparation of non-βphosphonium functionalized rhodaand irida-carbolong complexes.Herein,a one-pot strategy,by mixing a multiyne,a nucleophile,and Rhcl(CO)(PPh_(3))_(2)/AgBF_(4)or[Ir(CH:CN)(CO)(PPh_(3))_(2)]BF_(4),was developed to achieve a series ofβfunctionalized rhoda-and irida-carbolong complexes.Theβ-substituents in these complexes can be various C-,N-and O-centered groups,dependent on the nucleophiles used.This strategy provides a new convenient route to construct carbolong complexes,which is important for the further development of carbolong chemistry.
基金supported by the National Natural Science Foundation of China(U1705254,21871225,and 21931002)the Fundamental Research Funds for the Central Universities(20720190042),and the Research Grants Council of Hong Kong(N_HKUST603/15).
文摘Three-membered unsaturated rings have been widely utilized in organic synthesis due to their inherent highly strained structures.Although much research has been applied to ring-expansion reactions of such strained ring systems,pathways other than[3+2]cycloadditions have rarely been observed in their reactions with alkynes,and to date,no[3+1]cycloadditions of isolated three-membered unsaturated rings with alkynes have been reported.Here we demonstrate an unprecedented[3+1]cycloaddition in which a fused metalla-azirine is used as a template to generate a series of planar CCCCX-type(X=N,O,S)pentadentate carbolong complexes 3–6.A series of substituted alkynes was tested for further exploration of the scope and mechanism for the[3+1]cycloaddition reactions.Complexes 3–6 represent rare examples of planar pentadentate complexes that assemble fourπ-conjugated fused rings by one bridgehead atom.These novel complexes are thermally stable in air and absorb ultraviolet,visible,and near-infrared light,and thus are potentially applicable in photoelectric devices and pharmaceuticals.