Highly Diastereo- and Enantioselective Synthesis of Tetrahydrobenzo[b]azocines via Palladium-Catalyzed [4 + 4] Cycloaddition
作者:Can Gao、Xunhua Wang、Jitian Liu、Xiaoxun Li
DOI:10.1021/acscatal.0c05515
日期:2021.3.5
The construction of N-heterocyclic eight-membered rings with good regio-, stereo-, and enantioselective control remains a formidable challenge in asymmetric catalysis. Herein, we report a palladium-catalyzed asymmetric [4 + 4] cycloaddition of anthranils with γ-methylidene-δ-valerolactones in the presence of Et3B, delivering highly functionalized tetrahydrobenzo[b]azocine derivatives in high efficiency
Palladium-catalyzed Decarboxylative [4+1] Cyclization of γ-Methylidene-δ-valerolactones with Isocyanides
作者:Soyoung Park、Ryo Shintani、Tamio Hayashi
DOI:10.1246/cl.2009.204
日期:2009.3.5
A palladium-catalyzed decarboxylative cyclization of γ-methylidene-δ-valerolactones with isocyanides has been developed to afford conjugated cyclopentenimines under mild conditions. Some preliminary results toward the development of an asymmetric variant have also been described.
Palladium-Catalyzed Asymmetric (4 + 2) Annulation of γ-Methylidene-δ-valerolactones with Alkenes: Enantioselective Synthesis of Functionalized Chiral Cyclohexyl Spirooxindoles
作者:Zhi-Long Jia、Xian-Tao An、Yu-Hua Deng、Lin-Han Pang、Chun-Fang Liu、Le-Le Meng、Jia-Kun Xue、Xian-He Zhao、Chun-An Fan
DOI:10.1021/acs.orglett.0c03963
日期:2021.2.5
(S,S,S)-(−)-Xyl-SKP, offering a new approach for the diastereo- and enantioselective synthesis of chiral cyclohexadienone-fused cyclohexyl spirooxindoles. Significantly, three highly congested contiguous tetrasubstituted carbonatoms embedded in bispirocyclic skeleton, of which two are vicinalquaternarystereogenic centers, are forged in an effective and selective manner (up to 99% yield, up to 95%
Palladium-Catalyzed Synthesis of 4-Oxaspiro[2.4]heptanes via Central Attack of Oxygen Nucleophiles to π-Allylpalladium Intermediates
作者:Ryo Shintani、Tomoaki Ito、Tamio Hayashi
DOI:10.1021/ol300852v
日期:2012.5.4
cyclopropanation of γ-methylidene-δ-valerolactones with aromatic aldehydes has been developed to give 4-oxaspiro[2.4]heptanes with high selectivity. The site of nucleophilic attack to a π-allylpalladium intermediate has been controlled with a sterically demanding phosphine ligand. The course of the reaction is highly dependent on ligands and solvents, and selective formation of methylenetetrahydropyrans has
Gold and Palladium Relay Catalytic [4 + 4] Cycloadditions of Enynamides and γ-Methylene-δ-valerolactones: Diastereoselective Construction of Furan-Fused Azacyclooctanes
subsequently participate in diastereoselective formal [4 + 4] cycloadditions with γ-methylene-δ-valerolactones. This strategy enables the rapid and efficient construction of a series of furan-fused azacyclooctanes with diverse substituents in good yields (63–97%) and a high level of diastereoselectivity (7:1 → 20:1 dr).