Palladium-Catalyzed [5 + 2] Annulation of Vinylethylene Carbonates with Barbiturate-Derived Alkenes
摘要:
A palladium/XantPhos-catalyzed [5 + 2] annulation of VECs with electron-deficient alkenes having an isolated carbon-carbon double bond has been developed to afford spirobarbiturate-tetrahydrooxepines. This study provides an expedient assembly of biologically interesting spirobarbiturate-tetrahydrooxepines. The easy scalability and versatile transformability of the reaction products were also exhibited.
Palladium-Catalyzed Diastereoselective Formal [5 + 3] Cycloaddition for the Construction of Spirooxindoles Fused with an Eight-Membered Ring
作者:Ben Niu、Xiao-Yun Wu、Yin Wei、Min Shi
DOI:10.1021/acs.orglett.9b01748
日期:2019.6.21
A Pd-catalyzed formal [5 + 3] intermolecular cycloaddition reaction of isatin-derived α-(trifluoromethyl)imines with aryl substituted vinylethylene carbonates (VECs) has been reported, affording trifluoromethyl-group-containing spirooxindoles fused with an eight-membered ring as a single diastereoisomer in good yields in the presence of a Brønsted acid in a one-pot manner under mild conditions. The
Chiral Bidentate Phosphoramidite-Pd Catalyzed Asymmetric Decarboxylative Dipolar Cycloaddition for Multistereogenic Tetrahydrofurans with Cyclic <i>N</i>-Sulfonyl Ketimine Moieties
作者:Hao-Peng Lv、Xiao-Peng Yang、Bai-Lin Wang、Hao-Di Yang、Xing-Wang Wang、Zheng Wang
DOI:10.1021/acs.orglett.1c01411
日期:2021.6.18
An asymmetric [3 + 2] cycloaddition of vinyl ethylenecarbonates (VECs) and (E)-3-arylvinyl substituted benzo[d] isothiazole 1,1-dioxides has been developed using the Pd complex of a bidentate phosphoramidite (Me-BIPAM) as the catalyst, providing a wide variety of chiral multistereogenic vinyltetrahydrofurans in good yields with excellent diastereo- and enantioselectivities (up to >20:1 dr, 99% ee)
A diastereoselective (3 + 2) cycloaddition of N-sulfonyl ketimines with vinylethylene carbonates (VECs) in the presence of Pd2dba3·CHCl3 and PPh3 has been developed. The reaction of various substituted VECs and diverse cyclic N-sulfonyl ketimines proceeded smoothly under mild conditions, giving highly functionalized oxazolidine frameworks in good to excellent yields with moderate to good diastereoselectivities
Asymmetric Synthesis of N‐Fused 1,3‐Oxazolidines via Pd‐Catalyzed Decarboxylative (3+2) Cycloaddition
作者:Jong‐Un Park、Hye‐In Ahn、Ho‐Jun Cho、Zi Xuan、Ju Hyun Kim
DOI:10.1002/adsc.201901497
日期:2020.4.27
Efficient synthesis of optically active N‐fused 1,3‐oxazolidines containing quaternary and tertiary stereocenters was achieved via Pd‐catalyzed asymmetric (3+2) cycloadditions of sulfamate‐derived cyclic imines and vinylethylene carbonates. Using a chiral phosphoramidite ligand, the cycloadditions proceeded effectively providing sulfamidate‐fused 1,3‐oxazolidines in high yields (up to 96%) with stereoselectivities
Palladium‐Catalyzed Decarboxylative Cycloaddition of Vinylethylene Carbonates with Formaldehyde: Enantioselective Construction of Tertiary Vinylglycols
An efficient method for the enantioselectiveconstruction of tertiaryvinylglycols through a palladium‐catalyzed asymmetric decarboxylativecycloaddition of vinylethylenecarbonates with formaldehyde was developed. By using a palladium complex generated in situ from [Pd2(dba)3]⋅CHCl3 and a phosphoramidite ligand as a catalyst under mild reaction conditions, the process allows conversion of racemic