A chiral Brønsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with <i>in situ</i> generated <i>N</i>-acyl ketimines
作者:Rajshekhar A. Unhale、Milon M. Sadhu、Sumit K. Ray、Rayhan G. Biswas、Vinod K. Singh
DOI:10.1039/c8cc01436a
日期:——
A chiral phosphoric acid-catalyzed asymmetricMannich-typereaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-hydroxyisoindolinones has been demonstrated in this communication. A variety of isoindolinone-based α-amino diazo esters bearing a quaternary stereogenic center were afforded in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee). Furthermore
Enantioselective Trapping of Oxonium Ylides by 3-Hydroxyisoindolinones via a Formal S<sub>N</sub>1 Pathway for Construction of Contiguous Quaternary Stereocenters
作者:Zhenghui Kang、Dan Zhang、Jiayi Shou、Wenhao Hu
DOI:10.1021/acs.orglett.7b03916
日期:2018.2.16
acid co-catalyzed three-componentreaction via trapping of oxoniumylides with 3-hydroxyisoindolinones by a formal SN1 pathway is described. This reaction allows for the efficientsynthesis of isoindolinone derivatives with two contiguous quaternary stereogenic centers in high yields (up to 93%) with excellent enantioselectivities and moderate diastereoselectivities under mild reaction conditions.
A chiral SPINOL derived phosphoric acid-catalyzed asymmetric N-alkylation reaction of indoles with cyclic α-diaryl-substituted N-acyl imines, which are generated in situ from 3-aryl 3-hydroxyisoindolinones, has been demonstrated. The transformation proceeds smoothly with a broad range of indoles and isoindolinone alcohols. A variety of indole derived N-alkylated tetrasubstituted chiral aminals were
Enantioselective Synthesis of Difluoroalkylated Isoindolinones via Chiral Spirocyclic Phosphoric Acid Catalyzed Mannich-Type Reaction
作者:Xufeng Lin、Lei Wang、Jialing Zhong
DOI:10.1055/a-1274-2959
日期:2021.3
An enantioselective Mannich-type reaction of in situ generated cyclic ketimines with difluoroenoxysilanes catalyzed by chiral spirocyclic phosphoric acid has been developed. This methodology provides a facile route to difluoroalkyl-substituted chiral isoindolinones bearing a quaternary stereogenic center in high yields and up to 96% enantioselectivity.