83164-91-4Relevant academic research and scientific papers
Base-catalyzed dehydration of 3-substituted benzene cis -1,2-dihydrodiols: Stabilization of a cyclohexadienide anion intermediate by negative aromatic hyperconjugation
Kudavalli, Jaya Satyanarayana,Rao, S. Nagaraja,More Oferrall, Rory A.,Bean, David E.,Fowler, Patrick W.,Sharma, Narain D.,Boyd, Derek R.,Kamerlin, Shina Caroline Lynn,Keeffe, James R.,Gronert, Scott
, p. 14056 - 14069,14 (2012)
Evidence that a 1,2-dihydroxycyclohexadienide anion is stabilized by aromatic "negative hyperconjugation" is described. It complements an earlier inference of "positive" hyperconjugative aromaticity for the cyclohexadienyl cation. The anion is a reactive intermediate in the dehydration of benzene cis-1,2-dihydrodiol to phenol. Rate constants for 3-substituted benzene cis-dihydrodiols are correlated by σ- values with = 3.2. Solvent isotope effects for the reactions are kH2O/kD 2O = 1.2-1.8. These measurements are consistent with reaction via a carbanion intermediate or a concerted reaction with a "carbanion-like" transition state. These and other experimental results confirm that the reaction proceeds by a stepwise mechanism, with a change in rate-determining step from proton transfer to the loss of hydroxide ion from the intermediate. Hydrogen isotope exchange accompanying dehydration of the parent benzene cis-1,2-dihydrodiol was not found, and thus, the proton transfer step is subject to internal return. A rate constant of ~1011 s-1, corresponding to rotational relaxation of the aqueous solvent, is assigned to loss of hydroxide ion from the intermediate. The rate constant for internal return therefore falls in the range 1011-1012 s -1. From these limiting values and the measured rate constant for hydroxide-catalyzed dehydration, a pKa of 30.8 ± 0.5 was determined for formation of the anion. Although loss of hydroxide ion is hugely exothermic, a concerted reaction is not enforced by the instability of the intermediate. Stabilization by negative hyperconjugation is proposed for 1,2-dihydroxycyclohexadienide and similar anions, and this proposal is supported by additional experimental evidence and by computational results, including evidence for a diatropic ("aromatic") ring current in 3,3-difluorocyclohexadienyl anion.
Design and Identification of a Novel, Functionally Subtype Selective GABAA Positive Allosteric Modulator (PF-06372865)
Owen, Robert M.,Blakemore, David,Cao, Lishuang,Flanagan, Neil,Fish, Rebecca,Gibson, Karl R.,Gurrell, Rachel,Huh, Chan Woo,Kammonen, Juha,Mortimer-Cassen, Elisabeth,Nickolls, Sarah A.,Omoto, Kiyoyuki,Owen, Dafydd,Pike, Andy,Pryde, David C.,Reynolds, David S.,Roeloffs, Rosemarie,Rose, Colin,Stead, Clara,Takeuchi, Mifune,Warmus, Joseph S.,Watson, Christine
supporting information, p. 5773 - 5796 (2019/05/15)
The design, optimization, and evaluation of a series of novel imidazopyridazine-based subtype-selective positive allosteric modulators (PAMs) for the GABAA ligand-gated ion channel are described. From a set of initial hits multiple subseries were designed and evaluated based on binding affinity and functional activity. As designing in the desired level of functional selectivity proved difficult, a probability-based assessment was performed to focus the project's efforts on a single subseries that had the greatest odds of delivering the target profile. These efforts ultimately led to the identification of two precandidates from this subseries, which were advanced to preclinical safety studies and subsequently to the identification of the clinical candidate PF-06372865.
MODULATORS OF THE BETA-3 ADRENERGIC RECEPTOR USEFUL FOR THE TREATMENT OR PREVENTION OF DISORDERS RELATED THERETO
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Page/Page column 93; 120, (2018/01/17)
The present invention relates to compounds of Formula (Ia) and pharmaceutical compositions thereof that modulate the activity of the beta-3 adrenergic receptor. Compounds of the present invention and pharmaceutical compositions thereof are directed to methods useful in the treatment of a beta-3 adrenergic receptor-mediated disorder, such as, heart failure; cardiac performance in heart failure; mortality, reinfarction, and/or hospitalization in connection with heart failure; acute heart failure; acute decompensated heart failure; congestive heart failure; severe congestive heart failure; organ damage associated with heart failure (e.g., kidney damage or failure, heart valve problems, heart rhythm problems, and/or liver damage); heart failure due to left ventricular dysfunction; heart failure with normal ejection fraction; cardiovascular mortality following myocardial infarction; cardiovascular mortality in patients with left ventricular failure or left ventricular dysfunction; left ventricular failure; left ventricular dysfunction; class II heart failure using the New York Heart Association (NYHA) classification system; class III heart failure using the New York Heart Association (NYHA) classification system; class IV heart failure using the New York Heart Association (NYHA) classification system; LVEF 40% by radionuclide ventriculography; LVEF ≤35% by echocardiography or ventricular contrast angiography; and conditions related thereto.
