408335-66-0Relevant academic research and scientific papers
Enantioselective Intermolecular Excited-State Photoreactions Using a Chiral Ir Triplet Sensitizer: Separating Association from Energy Transfer in Asymmetric Photocatalysis
Zheng, Jian,Swords, Wesley B.,Jung, Hoimin,Skubi, Kazimer L.,Kidd, Jesse B.,Meyer, Gerald J.,Baik, Mu-Hyun,Yoon, Tehshik P.
supporting information, p. 13625 - 13634 (2019/08/26)
Enantioselective catalysis of excited-state photoreactions remains a substantial challenge in synthetic chemistry, and intermolecular photoreactions have proven especially difficult to conduct in a stereocontrolled fashion. Herein, we report a highly enantioselective intermolecular [2 + 2] cycloaddition of 3-alkoxyquinolones catalyzed by a chiral hydrogen-bonding iridium photosensitizer. Enantioselectivities as high as 99% ee were measured in reactions with a range of maleimides and other electron-deficient alkene reaction partners. An array of kinetic, spectroscopic, and computational studies supports a mechanism in which the photocatalyst and quinolone form a hydrogen-bonded complex to control selectivity, yet upon photoexcitation of this complex, energy transfer sensitization of maleimide is preferred. The sensitized maleimide then reacts with the hydrogen-bonded quinolone-photocatalyst complex to afford a highly enantioenriched cycloadduct. This finding contradicts a long-standing tenet of enantioselective photochemistry that held that stereoselective photoreactions require strong preassociation to the sensitized substrate in order to overcome the short lifetimes of electronically excited organic molecules. This system therefore suggests that a broader range of alternate design strategies for asymmetric photocatalysis might be possible.
Enantioselective Excited-State Photoreactions Controlled by a Chiral Hydrogen-Bonding Iridium Sensitizer
Skubi, Kazimer L.,Kidd, Jesse B.,Jung, Hoimin,Guzei, Ilia A.,Baik, Mu-Hyun,Yoon, Tehshik P.
supporting information, p. 17186 - 17192 (2017/12/06)
Stereochemical control of electronically excited states is a long-standing challenge in photochemical synthesis, and few catalytic systems that produce high enantioselectivities in triplet-state photoreactions are known. We report herein an exceptionally effective chiral photocatalyst that recruits prochiral quinolones using a series of hydrogen-bonding and π-π interactions. The organization of these substrates within the chiral environment of the transition-metal photosensitizer leads to efficient Dexter energy transfer and effective stereoinduction. The relative insensitivity of these organometallic chromophores toward ligand modification enables the optimization of this catalyst structure for high enantiomeric excess at catalyst loadings as much as 100-fold lower than the optimal conditions reported for analogous chiral organic photosensitizers.
Discovery, SAR, and pharmacokinetics of a novel 3-hydroxyquinolin-2(1H)-one series of potent D-amino acid oxidase (DAAO) inhibitors
Duplantier, Allen J.,Becker, Stacey L.,Bohanon, Michael J.,Borzilleri, Kris A.,Chrunyk, Boris A.,Downs, James T.,Hu, Lain-Yen,El-Kattan, Ayman,James, Larry C.,Liu, Shenping,Lu, Jiemin,Maklad, Noha,Mansour, Mahmoud N.,Mente, Scot,Piotrowski, Mary A.,Sakya, Subas M.,Sheehan, Susan,Steyn, Stefanus J.,Strick, Christine A.,Williams, Victoria A.,Zhang, Lei
experimental part, p. 3576 - 3585 (2010/03/30)
3-Hydroxyquinolin-2(1H)-one (2) was discovered by high throughput screening in a functional assay to be a potent inhibitor of human DAAO, and its binding affinity was confirmed in a Biacore assay. Cocrystallization of 2 with the human DAAO enzyme defined
