We demonstrate that a bulky cyclic amino ligand,specifically 1,1,3,3-tetraphenylisoindolinyl,can facilitate the formation of a transient stannyne,endowed with adjacent ambiphilic carbon and tin centers.This stannyne,m...We demonstrate that a bulky cyclic amino ligand,specifically 1,1,3,3-tetraphenylisoindolinyl,can facilitate the formation of a transient stannyne,endowed with adjacent ambiphilic carbon and tin centers.This stannyne,manifesting carbene-like behavior,engages in an unprecedented sequence of reactions,including Buchner ring expansion,[1,3]sigmatropic,and[1,5]-sigmatropic shifts,culminating in the synthesis of a stable cyclic(alkyl)(amino)stannylene.This compound represents the first tin analogue of the well-known cyclic(alkyl)(amino)carbenes.Both the bonding configuration and the formation process of this stannylene are thoroughly analyzed through quantum chemical computations.Our findings pave the way for further synthesis of unusual main group species using bulky isoindolinyl substituents,emphasizing their potential as a versatile tool in synthetic chemistry.展开更多
X2Si=Sn:(X = H, Me, F, Cl, Br, Ph, Ar…) are new species of chemistry. The cycloaddition reaction of X2Si=Sn: is a new study field of stannylene chemistry. To explore the rules of cycloaddition reaction between X2Si=S...X2Si=Sn:(X = H, Me, F, Cl, Br, Ph, Ar…) are new species of chemistry. The cycloaddition reaction of X2Si=Sn: is a new study field of stannylene chemistry. To explore the rules of cycloaddition reaction between X2Si=Sn: and the symmetric p-bonded compounds, the cycloaddition reactions of Cl2Si=Sn: and ethylene were selected as model reactions in this paper.The mechanism of cycloaddition reaction between singlet Cl2Si=Sn: and ethylene has been first investigated with the MP2/GENECP(C, H, Cl, Si in 6-311++G**;Sn in LanL2dz) method in this paper. From the potential energy profile, it could be predicted that the reaction has one dominant reaction channel. The reaction rule presented is that the 5p unoccupied orbital of Sn in Cl2Si=Sn: and the π orbital of ethylene forming a p→p donor-acceptor bond, resulting in the formation of an intermediate. Instability of the intermediate makes it isomerize to a four-membered Si-heterocyclic ring stannylene. Because the 5p unoccupied orbital of Sn atom in the four-membered Si-heterocyclic ring stannylene and the π orbital of ethylene form a p→p donor-acceptor bond, the four-membered Si-heterocyclic ring stannylene further combines with ethene to form another intermediate. Because the Sn atom in the intermediate shows sp3 hybridization after transition state, the intermediate isomerizes to a Si-heterocyclic spiro-Sn-heterocyclic ring compound. The research result indicates the laws of cycloaddition reaction between X2Si=Sn: and the symmetric π-bonded compounds. The study opens up a new research field for stannylene chemistry.展开更多
基金supported by the National Natural Science Foundation of China(22350004,22101114,22271132)the ShenzhenScienceandTechnologyInnovationProgram(20231120110042001)+1 种基金the High Level of Special Funds(G03050K003)the Guangdong Innovation and Entrepreneurial Research Team Program(2021ZT09C278)。
文摘We demonstrate that a bulky cyclic amino ligand,specifically 1,1,3,3-tetraphenylisoindolinyl,can facilitate the formation of a transient stannyne,endowed with adjacent ambiphilic carbon and tin centers.This stannyne,manifesting carbene-like behavior,engages in an unprecedented sequence of reactions,including Buchner ring expansion,[1,3]sigmatropic,and[1,5]-sigmatropic shifts,culminating in the synthesis of a stable cyclic(alkyl)(amino)stannylene.This compound represents the first tin analogue of the well-known cyclic(alkyl)(amino)carbenes.Both the bonding configuration and the formation process of this stannylene are thoroughly analyzed through quantum chemical computations.Our findings pave the way for further synthesis of unusual main group species using bulky isoindolinyl substituents,emphasizing their potential as a versatile tool in synthetic chemistry.
基金supported by the National Natural Science Foundation of China(No.51102114)
文摘X2Si=Sn:(X = H, Me, F, Cl, Br, Ph, Ar…) are new species of chemistry. The cycloaddition reaction of X2Si=Sn: is a new study field of stannylene chemistry. To explore the rules of cycloaddition reaction between X2Si=Sn: and the symmetric p-bonded compounds, the cycloaddition reactions of Cl2Si=Sn: and ethylene were selected as model reactions in this paper.The mechanism of cycloaddition reaction between singlet Cl2Si=Sn: and ethylene has been first investigated with the MP2/GENECP(C, H, Cl, Si in 6-311++G**;Sn in LanL2dz) method in this paper. From the potential energy profile, it could be predicted that the reaction has one dominant reaction channel. The reaction rule presented is that the 5p unoccupied orbital of Sn in Cl2Si=Sn: and the π orbital of ethylene forming a p→p donor-acceptor bond, resulting in the formation of an intermediate. Instability of the intermediate makes it isomerize to a four-membered Si-heterocyclic ring stannylene. Because the 5p unoccupied orbital of Sn atom in the four-membered Si-heterocyclic ring stannylene and the π orbital of ethylene form a p→p donor-acceptor bond, the four-membered Si-heterocyclic ring stannylene further combines with ethene to form another intermediate. Because the Sn atom in the intermediate shows sp3 hybridization after transition state, the intermediate isomerizes to a Si-heterocyclic spiro-Sn-heterocyclic ring compound. The research result indicates the laws of cycloaddition reaction between X2Si=Sn: and the symmetric π-bonded compounds. The study opens up a new research field for stannylene chemistry.
