Chiral Naphthyl-C2-Indole as Scaffold for Phosphine Organocatalysis: Application in Asymmetric Formal [4 + 2] Cycloaddition Reactions
作者:Tingting He、Lei Peng、Shan Li、Fangli Hu、Chuandong Xie、Shengli Huang、Shiqi Jia、Wenling Qin、Hailong Yan
DOI:10.1021/acs.orglett.0c02519
日期:2020.9.4
naphthyl-C2-indole bifunctional phosphine organocatalyst in stereoselective formal [4 + 2] cycloadditionreactions were reported. The chiral naphthyl-C2-indole skeleton was introduced to bifunctional phosphine organocatalysis for the first time, and excellent stereocontrol was achieved in two types of formal [4 + 2] cycloadditionreactions. With the optimal catalyst, a series of chiral spirooxindole and hydrodibenzofuran
Metal-free difunctionalization of alkynes to access tetrasubstituted olefins through spontaneous selenosulfonylation of vinylidene <i>ortho</i>-quinone methide (VQM)
difunctionalization of alkynes to access tetrasubstituted olefins through spontaneous selenosulfonylation of vinylidene ortho-quinone methide (VQM) was described herein. The reaction was conducted under mild conditions without any catalysts or additives. Preliminary mechanism studies revealed that the formation of VQM was the key for this alkyne di-functionalization reaction. The reaction could be applied
本文描述了炔烃的无金属双官能化,以通过亚乙烯基邻甲基醌(VQM)的自发硒代磺酰基化来获得四取代的烯烃。反应在温和条件下进行,没有任何催化剂或添加剂。初步的机理研究表明,VQM的形成是这种炔烃双官能化反应的关键。该反应可用于轴向手性苯乙烯的对映选择性不对称合成。此外,硒代磺酰化加合物可以转化为有用的萘[2,1- b ]呋喃和苯并呋喃支架。
Synthesis and Stereochemical Behavior of a New Chiral Oxa[7]heterohelicene
A new chiral oxa[7]heterohelicene 1b was synthesized by catalytic aerobic-oxidative tandem cyclization of the o-phenylene-linked bis(2-naphthol) derivative 3 with palladium acetate in dimethyl sulf...
Enantioselective Control of Both Helical and Axial Stereogenic Elements though an Organocatalytic Approach
作者:Shiqi Jia、Shan Li、Yidong Liu、Wenling Qin、Hailong Yan
DOI:10.1002/anie.201909214
日期:2019.12.16
molecules containing helicenes and stereogenic axes was developed based on organocatalysis. Various compounds bearing bothhelical and axialstereogenicelements were obtained in excellent enantioselectivities. The mechanism study revealed that the reaction proceeded through two stages: 1) The first cyclization produces a reaction intermediate containing a stereogenic axis. 2) The dynamic kinetic resolution
Organocatalytic Atroposelective Intramolecular [4+2] Cycloaddition: Synthesis of Axially Chiral Heterobiaryls
作者:Yidong Liu、Xiaoyan Wu、Shan Li、Lu Xue、Chunhui Shan、Zhengxing Zhao、Hailong Yan
DOI:10.1002/anie.201801824
日期:2018.5.28
The enantioselective construction of axially chiral aryl‐naphthopyran skeletons was realized by organocatalytic atroposelective intramolecular [4+2] cycloaddition of in situ generated vinylidene ortho‐quinone methides, from 2‐ethynylphenol derivatives, with alkynes. Through this method, the heteroatropisomers were obtained with excellent yields and enantioselectivities. Moreover, a speculative model