Axially chiral styrene-based organocatalysts and their application in asymmetric cascade Michael/cyclization reaction
Yu Hao1, Zi-Hao Li1, Zhi-Gang Ma1
1Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University Shanghai 200240 P. R. China zhangsy16@sjtu.edu.cn.
Abstract:
An axially chiral styrene-based organocatalyst, featuring a combination of axially chiral styrene-based structure and a pyrrole ring, has been designed and synthesized. This catalyst demonstrates remarkable capabilities in producing a wide range of densely substituted spirooxindoles that feature an alkyne-substituted quaternary stereogenic center. These spirooxindoles are generated through mild cascade Michael/cyclization reactions, resulting in high conversion rates and exceptional enantioselectivity. Our catalytic model, based on experiments, X-ray structure analysis and DFT calculations suggests that chiral matched π-π interactions and multiple H-bonds between the organocatalyst and substrates play significant roles in controlling the stereoselectivity of the reaction.
More Related Videos
06:31Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators
Published on: November 27, 2015
09:14Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
Published on: February 16, 2018
Related Concept Videos
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
01:27Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
01:29Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
01:28Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
02:36Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...