Synthesis of Metal-Free Chiral Covalent Organic Framework for Visible-Light-Mediated Enantioselective Photooxidation in Water

Abstract

Although chiral covalent organic frameworks (CCOFs) presence grows in thermal asymmetric catalysis, their application in equally important asymmetric photocatalysis has yet to begin. Herein, we first report a propargylamine-linked and quaternary ammonium bromide decorated porphyrin-CCOF which can highly promote visible-light-driven enantioselective photooxidation of sulfides to sulfoxides in water and in air. This methodology has also been applied to the synthesis of (R)modafinil, a wakefulness-promoting medication used for the treatment of excessive sleepiness. This research might open a new way for the application of CCOFs in asymmetric photocatalysis.

Boosting the photocatalytic performance via isomeric configuration design in covalent organic frameworks

“…Benefitting from the advantages of light weight, strong crystallinity, high surface area, easy recyclability and tunable bandgaps, [1][2][3][4] covalent organic frameworks (COFs) have obtained tremendous research attentions, since the first COF was successfully synthesized by Yaghi et al in 2005. 5 With the merits of readily adjustable photoelectric properties and permanent porosity, COFs have been widely applied in the photocatalytic fields 6 of hydrogen evolution, 7,8 CO 2 reduction, 9,10 pollution degradation 11 and organic transformations [12][13][14][15] in the past decade. Although a diversity of exciting research progresses has been achieved, it is still a challenge to clearly illustrate the structure-property relationships of the COF materials, which is beneficial for developing COFs with remarkable activities.…”

Rhodium-catalyzed enantioselective C–H alkynylation of sulfoxides in diverse patterns: desymmetrization, kinetic resolution, and parallel kinetic resolution

“…The (R) conguration of a recovered sulfoxide substrate 4m was determined based on a previous report. 21 To further broaden the substrate scope and the asymmetric reaction patterns, biased diaryl sulfoxides were then examined toward dynamic kinetic resolution since both arene rings may undergo competitive alkynylation (Scheme 4). Indeed, the alkynylation occurred at both arene rings under the standard reaction conditions, furnishing products 7 and 8 in a parallel kinetic resolution (PKR) fashion.…”

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

“…Very recently, the same group disclosed that CCOFs can be prepared by a catalytic asymmetric polymerization approach. 44,681 With the aid of the chiral 2-methylpyrrolidine catalyst, a series of tris(N-salicylideneamine)-derived b-ketoenamine-linked CCOFs were directly synthesized from prochiral aldehyde and primary amine monomers in high yields under ambient conditions. 682 The obtained (L)-and (D)-TpPa-1 with the b-ketoenamine coordination moiety were further metalated by copper(II) trifluoromethanesulfonate in hot ethanol to give the corresponding This journal is © The Royal Society of Chemistry 2022 Cu(II)-metalated CCOFs.…”