Photocatalytic Supramolecular Enantiodifferentiating Dimerization of 2-Anthracenecarboxylic Acid through Triplet–Triplet Annihilation
作者:Ming Rao、Kuppusamy Kanagaraj、Chunying Fan、Jiecheng Ji、Chao Xiao、Xueqin Wei、Wanhua Wu、Cheng Yang
DOI:10.1021/acs.orglett.8b00520
日期:2018.3.16
Visible-light-driven enantiodifferentiating photodimerization of 2-anthracenecarboxylic acid (AC) sensitized by Schiff base Pt(II) complex-grafted γ-cyclodextrins leads the first triplet–triplet annihilation-based catalytic photochirogenesis. The syn-head-to-tail (HT) photodimer 2 was achieved in up to 31.4% ee at 61.0% conversion in the presence of 0.5% equiv of the photocatalyst.
pH-Controlled Chirality Inversion in Enantiodifferentiating Photocyclodimerization of 2-Antharacenecarboxylic Acid Mediated by γ-Cyclodextrin Derivatives
derivatives were used as chiral hosts for the photocyclodimerization of 2-anthracenecarboxylic acid (AC). The effect of pH on photoreactivity and stereochemical outcome of photoproducts was investigated. Upon changing the solution pH, the stereochemical outcome of HH cyclodimer 3 was inverted from 25.2% to −64.4% and 41.2% to −76.2%, respectively, in the photocyclodimerization of AC mediated by bis-quinoline-modified
Switched enantioselectivity by solvent components and temperature in photocyclodimerization of 2-anthracenecarboxylate with 6 A ,6 X -diguanidio− γ -cyclodextrins
-cyclodextrins (CDs) were used as chiral hosts for mediating the enantiodifferentiating [4 + 4] photocyclodimerization of 2-anthracenecarboxylic acid (AC). These γ -CD derivatives form stable 1:2 ternary complexes with AC in aqueous ammonia solutions and the head-to-head photodimers 3 and 4 were greatly enhanced in the presence of these diguanidio- γ -CDs. The enantioselectivity of chiral photodimers 2 and 3 is