organocatalyst for the atom‐economic conversion of a plethora of alkyl‐ and aryl‐substituted epoxides and isocyanates into oxazolidinones is described. A mechanism was proposed wherein the nucleophilic ring‐opening operation, and oxo‐ and carbamate‐anions stabilization occur cooperatively towards isocyanate fixation.
of dynamiccovalent chemistry, with applications such as preparation of functional systems, dynamic materials, molecular machines, and covalent organic frameworks. However, acid catalysis is commonly needed for efficient equilibration of imine mixtures. Herein, it is demonstrated that hydrogen bond donors such as thioureas and squaramides can catalyze the equilibration of dynamic imine systems under
Squaramides as Potent Transmembrane Anion Transporters
作者:Nathalie Busschaert、Isabelle L. Kirby、Sarah Young、Simon J. Coles、Peter N. Horton、Mark E. Light、Philip A. Gale
DOI:10.1002/anie.201200729
日期:2012.4.27
Square peg in a round ball: Squaramides are shown to be potenttransmembraneaniontransporters for both chloride and bicarbonate, performing better than the thiourea and urea analogues. Studies into the nature of this transport point to a mobile carrier mechanism, where the squaramide delivers the anion cargo across the lipid bilayer (see scheme, green sphere=anion). These drug‐like molecules provide
The present application is directed to a method for producing non-isocyanate polyurethanes. More particularly, the application is directed to method for producing non-isocyanate polyurethanes by using a single catalyst component selected from an amidoindole derivative, a benzimidazole derivative and a squaramide derivative.
Light-Driven Photoconversion of Squaramides with Implications in Anion Transport
作者:Manel Vega、Luis Martínez-Crespo、Miguel Barceló-Oliver、Carmen Rotger、Antonio Costa
DOI:10.1021/acs.orglett.3c00993
日期:2023.5.19
Simple, clean and fast photoconversion of aniline-derived squaramides was achieved by flashlight illumination. UV irradiation enabled the photochemical squaramide ring-opening to generate 1,2-bisketenes, which DMSO trapped as the nucleophilic oxidant. The only photoproducts isolated were 3,4-arylamino maleic anhydrides, which present conformational preferences very different from those of their parent