203452-46-4Relevant articles and documents
Structure Kinetics Relationships and Molecular Dynamics Show Crucial Role for Heterocycle Leaving Group in Irreversible Diacylglycerol Lipase Inhibitors
Janssen, Antonius P.A.,Van Hengst, Jacob M.A.,Béquignon, Olivier J.M.,Deng, Hui,Van Westen, Gerard J.P.,Van Der Stelt, Mario
, p. 7910 - 7922 (2019/10/11)
Drug discovery programs of covalent irreversible, mechanism-based enzyme inhibitors often focus on optimization of potency as determined by IC50-values in biochemical assays. These assays do not allow the characterization of the binding activity (Ki) and reactivity (kinact) as individual kinetic parameters of the covalent inhibitors. Here, we report the development of a kinetic substrate assay to study the influence of the acidity (pKa) of heterocyclic leaving group of triazole urea derivatives as diacylglycerol lipase (DAGL)-α inhibitors. Surprisingly, we found that the reactivity of the inhibitors did not correlate with the pKa of the leaving group, whereas the position of the nitrogen atoms in the heterocyclic core determined to a large extent the binding activity of the inhibitor. This finding was confirmed and clarified by molecular dynamics simulations on the covalently bound Michaelis-Menten complex. A deeper understanding of the binding properties of covalent serine hydrolase inhibitors is expected to aid in the discovery and development of more selective covalent inhibitors.
Catalytic Asymmetric Synthesis of Morpholines. Using Mechanistic Insights to Realize the Enantioselective Synthesis of Piperazines
Lau, Ying Yin,Zhai, Huimin,Schafer, Laurel L.
, p. 8696 - 8709 (2016/10/14)
An efficient and practical catalytic approach for the enantioselective synthesis of 3-substituted morpholines through a tandem sequential one-pot reaction employing both hydroamination and asymmetric transfer hydrogenation reactions is described. Starting from ether-containing aminoalkyne substrates, a commercially available bis(amidate)bis(amido)Ti catalyst is utilized to yield a cyclic imine that is subsequently reduced using the Noyori-Ikariya catalyst, RuCl [(S,S)-Ts-DPEN] (η6-p-cymene), to afford chiral 3-substituted morpholines in good yield and enantiomeric excesses of >95%. A wide range of functional groups is tolerated. Substrate scope investigations suggest that hydrogen-bonding interactions between the oxygen in the backbone of the ether-containing substrate and the [(S,S)-Ts-DPEN] ligand of the Ru catalyst are crucial for obtaining high ee's. This insight led to a mechanistic proposal that predicts the observed absolute stereochemistry. Most importantly, this mechanistic insight allowed for the extension of this strategy to include N as an alternative hydrogen bond acceptor that could be incorporated into the substrate. Thus, the catalytic, enantioselective synthesis of 3-substituted piperazines is also demonstrated.
Stereoelectronic basis for the kinetic resolution of n-heterocycles with chiral acylating reagents
Hsieh, Sheng-Ying,Wanner, Benedikt,Wheeler, Philip,Beauchemin, Andre M.,Rovis, Tomislav,Bode, Jeffrey W.
supporting information, p. 7228 - 7231 (2014/06/23)
The kinetic resolution of N-heterocycles with chiral acylating agents reveals a previously unrecognized stereoelectronic effect in amine acylation. Combined with a new achiral hydroxamate, this effect makes possible the resolution of various N-heterocycles by using easily prepared reagents. A transition-state model to rationalize the stereochemical outcome of this kinetic resolution is also proposed.
