The recent development of microwave-assisted aqueous synthesis of polyheterocyclic-fused quinoline-2-thiones through 6π-electrocyclization was highlighted.
Comprehensive Summary.Herein,we have developed a facile method for the synthesis of various polysubstituted pyridine derivatives through selective 6π-electrocyclization of N-vinyl-α,β-unsaturated nitrones.It was fo...Comprehensive Summary.Herein,we have developed a facile method for the synthesis of various polysubstituted pyridine derivatives through selective 6π-electrocyclization of N-vinyl-α,β-unsaturated nitrones.It was found that gold catalysts promoted carbon-6π-electrocyclization of N-vinyl-α,β-unsaturated nitrones to afford 6-alkenyl pyridine N-oxides in 43%—75%yields,whereas copper catalysts facilitated oxygen-6π-electrocyclization to give 6-epoxy pyridines in 41%—83%yields.The present method features broad substrate scope,good functional group tolerance,high cyclization selectivity,and diversity of polysubstituted pyridine scaffolds.展开更多
The incorporation of trifluoromethyl groups into organic molecules represents a powerful strategy for modulating their physical,chemical,and biological properties.Although the 2H-pyran scaffold is a privileged structu...The incorporation of trifluoromethyl groups into organic molecules represents a powerful strategy for modulating their physical,chemical,and biological properties.Although the 2H-pyran scaffold is a privileged structure in bioactive compounds,practical methods for constructing trifluoromethylated 2H-pyrans remain limited.Herein,we report a palladium-catalyzed cascade reaction between trifluoroacetylsilanes and 1,3-enynes that efficiently produces diverse 6-CF_(3)-2H-pyrans in good yields.This transformation demonstrates broad substrate scope,excellent functional group tolerance,and high regio-and chemoselectivity.Computational studies reveal a reaction mechanism involving palladium-catalyzed C-Si insertion into the alkyne moiety,followed by oxa-6π-electrocyclization of the in situ generated trifluoromethylated oxatrienes.The synthetic utility of this methodology is further demonstrated through gram-scale synthesis and versatile downstream transformations.展开更多
文摘The recent development of microwave-assisted aqueous synthesis of polyheterocyclic-fused quinoline-2-thiones through 6π-electrocyclization was highlighted.
基金Financial support from the NSFC(22071035)Natural Science Foundation of Guangxi(2023GXNSFDA026025)+1 种基金Guangxi Science and Technology Plan Project(AD23026046)Guangxi Bagui Youth Scholar is greatly appreciated.
文摘Comprehensive Summary.Herein,we have developed a facile method for the synthesis of various polysubstituted pyridine derivatives through selective 6π-electrocyclization of N-vinyl-α,β-unsaturated nitrones.It was found that gold catalysts promoted carbon-6π-electrocyclization of N-vinyl-α,β-unsaturated nitrones to afford 6-alkenyl pyridine N-oxides in 43%—75%yields,whereas copper catalysts facilitated oxygen-6π-electrocyclization to give 6-epoxy pyridines in 41%—83%yields.The present method features broad substrate scope,good functional group tolerance,high cyclization selectivity,and diversity of polysubstituted pyridine scaffolds.
基金National Key R&D Program of China(grant no.2022YFA1506100)National Natural Science Foundation of China(grant nos.22471201,22531010,and 22503064)Fundamental Research Funds for the Central Universities(grant no.2042025kf0052)for financial support.The theoretical calculations were performed on the supercomputing system in the Supercomputing Center of Wuhan University.
文摘The incorporation of trifluoromethyl groups into organic molecules represents a powerful strategy for modulating their physical,chemical,and biological properties.Although the 2H-pyran scaffold is a privileged structure in bioactive compounds,practical methods for constructing trifluoromethylated 2H-pyrans remain limited.Herein,we report a palladium-catalyzed cascade reaction between trifluoroacetylsilanes and 1,3-enynes that efficiently produces diverse 6-CF_(3)-2H-pyrans in good yields.This transformation demonstrates broad substrate scope,excellent functional group tolerance,and high regio-and chemoselectivity.Computational studies reveal a reaction mechanism involving palladium-catalyzed C-Si insertion into the alkyne moiety,followed by oxa-6π-electrocyclization of the in situ generated trifluoromethylated oxatrienes.The synthetic utility of this methodology is further demonstrated through gram-scale synthesis and versatile downstream transformations.
