Primary amine-thiourea derivative 1 is an active and highly enantioselective catalyst for the conjugate addition of ketones to nitroalkenes. Broad substrate scope is described, with nitroalkenes bearing either aromatic or aliphatic substituents and a wide variety of ketones shown to be useful reacting partners. Ethyl ketones react preferentially, generating anti products with methyl-bearing stereocenters with good-to-excellent diastereoselectivity. An enamine mechanism is indicated, with cooperative activation of the electrophile by the thiourea and of the ketone by the primary amine.
DNA-encoded chemical
libraries (DELs) are a cost-effective technology
for the discovery of novel chemical probes and drug candidates. A
major limiting factor in assembling productive DELs is the availability
of DNA-compatible chemical reactions in aqueous media. In an effort
to increase the chemical accessibility and structural diversity of
small molecules displayed by DELs, we developed a robust Suzuki-Miyaura
reaction protocol that is compatible with the DNA structures. By employing
a water-soluble Pd-precatalyst, we developed conditions that allow
efficient coupling of DNA-linked aryl halides with a wide variety
of boronic acids/esters including heteroaryl boronates.
A series of potent hydroxyethyl amine (HEA) derived inhibitors
of β-site APP cleaving enzyme (BACE1) was optimized to address
suboptimal pharmacokinetics and poor CNS partitioning. This work identified
a series of benzodioxolane analogues that possessed improved metabolic
stability and increased oral bioavailability. Subsequent efforts focused
on improving CNS exposure by limiting susceptibility to Pgp-mediated
efflux and identified an inhibitor which demonstrated robust and sustained
reduction of CNS β-amyloid (Aβ) in Sprague–Dawley
rats following oral administration.
A structure- and property-based drug design approach was employed to identify aminooxazoline xanthenes as potent and selective human β-secretase inhibitors. These compounds exhibited good isolated enzyme, cell potency, and selectivity against the structurally related aspartyl protease cathepsin D. Our efforts resulted in the identification of a potent, orally bioavailable CNS penetrant compound that exhibited in vivo efficacy. A single oral dose of compound 11a resulted in a significant reduction of CNS Aβ40 in naive rats.
Because of its strong genetic validation, Na1.7 has attracted significant interest as a target for the treatment of pain. We have previously reported on a number of structurally distinct bicyclic heteroarylsulfonamides as Na1.7 inhibitors that demonstrate high levels of selectivity over other Na isoforms. Herein, we report the discovery and optimization of a series of atropisomeric quinolinone sulfonamide inhibitors [ Bicyclic sulfonamide compounds as sodium channel inhibitors and their preparation . WO 2014201206, 2014 ] of Na1.7, which demonstrate nanomolar inhibition of Na1.7 and exhibit high levels of selectivity over other sodium channel isoforms. After optimization of metabolic and pharmacokinetic properties, including PXR activation, CYP2C9 inhibition, and CYP3A4 TDI, several compounds were advanced into in vivo target engagement and efficacy models. When tested in mice, compound 39 (AM-0466) demonstrated robust pharmacodynamic activity in a Na1.7-dependent model of histamine-induced pruritus (itch) and additionally in a capsaicin-induced nociception model of pain without any confounding effect in open-field activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.