A low loading of a quinine-derived squaramide efficiently catalyzes the triple-domino Michael/aza-Henry/cyclization reaction between 1,3-dicarbonyl compounds, β-nitroolefins, and aldimines to provide tetrahydropyridines bearing three contiguous stereogenic centers in good yields, excellent enantiomeric excesses, and up to high diastereomeric ratios.
The first squaramide-decorated covalent organic framework has been successfully constructed, which exhibited excellent performance in biomimetic hydrogen-bonding organocatalysis.
第一个以方酰胺修饰的共价有机框架已成功构建,表现出在生物模拟氢键有机催化中的优异性能。
A Polystyrene-Supported, Highly Recyclable Squaramide Organocatalyst for the Enantioselective Michael Addition of 1,3-Dicarbonyl Compounds to β-Nitrostyrenes
作者:Pinar Kasaplar、Paola Riente、Caroline Hartmann、Miquel A. Pericàs
DOI:10.1002/adsc.201200526
日期:2012.11.12
A chiral squaramide has been supported onto a polystyrene (PS) resin through a copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction and used as a very active, easily recoverable and highly reusable organocatalyst for the asymmetric Michaeladdition of 1,3-dicarbonylcompounds to β-nitrostyrenes. The PS-supported squaramide could be recycled up to 10 times.
Molecular Engineering of β‐Substituted Oxoporphyrinogens for Hydrogen‐Bond Donor Catalysis
作者:Mandeep K. Chahal、Daniel T. Payne、Yoshitaka Matsushita、Jan Labuta、Katsuhiko Ariga、Jonathan P. Hill
DOI:10.1002/ejoc.201901706
日期:2020.1.9
Beta functionalization of oxoporphyrinogens as H‐bonddonor catalysts with binding site designed for dual activation of substrates is reported. Introduction of the β‐substituents enables the catalysis of 1,4‐conjugate additions, sulfa‐Michael additions and Henry/aza‐Henry reactions at low catalyst loadings (≤ 1 mol‐%) under mild conditions.
Graphene oxide as a recyclable phase transfer catalyst
作者:Youngmin Kim、Surajit Some、Hyoyoung Lee
DOI:10.1039/c3cc42787k
日期:——
We demonstrated a simple and green chemical method to obtain Michael adducts and their derivatives by using GO as a phase transfer catalyst with different kinds of bases in water and dichloromethane, and we also used GO multiple cycles almost without reduction in reaction yields.