Palladium-Catalyzed C–S Bond Cleavage with Allenoates: Synthesis of Tetrasubstituted 2-Alkenylfuran Derivatives
作者:Quannan Wang、Zhuqing Liu、Jiang Lou、Zhengkun Yu
DOI:10.1021/acs.orglett.8b02253
日期:2018.10.5
Palladium-catalyzed C–S cleavage of tetrasubstituted internal alkene α-oxo ketene dithioacetals was realized with allenoates as the coupling partners, efficiently affording tetrasubstituted 2-alkenylfuran derivatives with excellent regioselectivity under mild conditions. Allenoates acted as C1 synthons in the desulfurative [4 + 1] annulation.
Dearomatization of 3‐Nitroindoles by a Phosphine‐Catalyzed Enantioselective [3+2] Annulation Reaction
作者:Kaizhi Li、Théo P. Gonçalves、Kuo‐Wei Huang、Yixin Lu
DOI:10.1002/anie.201900248
日期:2019.4.8
The dearomatization of 3‐nitroindoles through a chiral‐phosphine‐mediated [3+2] annulationreaction is described. This method makes use of readily available 3‐nitroindoles as an aromatic feedstock and rapidly delivers a wide range of cyclopentaindoline alkaloid scaffolds in a highly enantioselective manner. Notably, phosphine‐triggered cyclization has not been utilized previously in a dearomatization
A convenient [3 + 2] annulation of azomethine ylides with allenoates promoted by triethylamine produced highly functionalized 2,5-dihydropyrrole derivatives in moderate to excellent yields under mild conditions. The potential utility of this reaction indicates that this reaction could be performed on the gram scale and the synthesized functionalized 2,5-dihydropyrrole derivatives could be further transformed
Phosphine‐Catalyzed (3+2) Annulation of Isoindigos with Allenes: Enantioselective Formation of Two Vicinal Quaternary Stereogenic Centers
作者:Wai‐Lun Chan、Xiaodong Tang、Fuhao Zhang、Glenn Quek、Guang‐Jian Mei、Yixin Lu
DOI:10.1002/anie.201900758
日期:2019.5.6
Construction of contiguous all‐carbon quaternary stereogenic centers is a long‐standing challenge in synthetic organic chemistry. In this report, a phosphine‐catalyzed enantioselective (3+2) annulation reaction between allenes and isoindigos, containing either two identical or different oxindole moieties, is introduced as a powerful strategy for the construction of spirocyclic bisindoline alkaloid
Redox Isomerization/(3+2) Allenoate Annulation by Auto‐Tandem Phosphine Catalysis
作者:Jeremy T. Maddigan‐Wyatt、Mitchell T. Blyth、Jhi Ametovski、Michelle L. Coote、Joel F. Hooper、David W. Lupton
DOI:10.1002/chem.202103224
日期:2021.11.22
mediates the redox isomerization of amino crotonates to give imines which then undergo (3+2) annulation with a range of allenoates in a second phosphine catalyzed process. Computational studies indicate that pivotal to the success of this reaction is the use of catalysts with similar ability to add to both allenoate and crotonate.