ABSTRACT
A novel rearrangement of 2-vinyl aziridine 2-carboxylates to unusual chiral cyclic sulfoximines is described herein. The method allows the synthesis of substituted cyclic sulfoximines in high yields with complete stereocontrol, and tolerates a wide substrate scope. A one-pot process starting directly from sulfinimines provides access to complex chiral sulfoximines in only two steps from commercially available aldehydes. A mechanistic hypothesis and synthetic application in the formal synthesis of trachelanthamidine, by transformation of a cyclic sulfoximine into a pyrroline, is also disclosed.
ABSTRACT
Identification of orthosteric mGlu(2/3) receptor agonists capable of discriminating between individual mGlu2 and mGlu3 subtypes has been highly challenging owing to the glutamate-site sequence homology between these proteins. Herein we detail the preparation and characterization of a series of molecules related to (1S,2S,5R,6S)-2-aminobicyclo[3.1.0]hexane-2,6-dicarboxylate 1 (LY354740) bearing C4-thiotriazole substituents. On the basis of second messenger responses in cells expressing other recombinant human mGlu2/3 subtypes, a number of high potency and efficacy mGlu2 receptor agonists exhibiting low potency mGlu3 partial agonist/antagonist activity were identified. From this, (1R,2S,4R,5R,6R)-2-amino-4-(1H-1,2,4-triazol-3-ylsulfanyl)bicyclo[3.1.0]hexane-2,6-dicarboxylic acid 14a (LY2812223) was further characterized. Cocrystallization of 14a with the amino terminal domains of hmGlu2 and hmGlu3 combined with site-directed mutation studies has clarified the underlying molecular basis of this unique pharmacology. Evaluation of 14a in a rat model responsive to mGlu2 receptor activation coupled with a measure of central drug disposition provides evidence that this molecule engages and activates central mGlu2 receptors in vivo.
Subject(s)
Bridged Bicyclo Compounds/chemistry , Receptors, Metabotropic Glutamate/agonists , Triazoles/chemistry , Allosteric Regulation , Animals , Binding, Competitive , Bridged Bicyclo Compounds/pharmacokinetics , Bridged Bicyclo Compounds/pharmacology , Calcium/metabolism , Cyclic AMP/metabolism , Dogs , Drug Partial Agonism , Humans , Male , Mice , Models, Molecular , Motor Activity/drug effects , Mutagenesis, Site-Directed , Protein Structure, Tertiary , Rats, Sprague-Dawley , Receptors, Metabotropic Glutamate/antagonists & inhibitors , Receptors, Metabotropic Glutamate/genetics , Receptors, Metabotropic Glutamate/metabolism , Stereoisomerism , Triazoles/pharmacokinetics , Triazoles/pharmacologyABSTRACT
As part of our ongoing research to identify novel agents acting at metabotropic glutamate 2 (mGlu2) and 3 (mGlu3) receptors, we have previously reported the identification of the C4α-methyl analog of mGlu2/3 receptor agonist 1 (LY354740). This molecule, 1S,2S,4R,5R,6S-2-amino-4-methylbicyclo[3.1.0]hexane-2,6-dicarboxylate 2 (LY541850), exhibited an unexpected mGlu2 agonist/mGlu3 antagonist pharmacological profile, whereas the C4ß-methyl diastereomer (3) possessed dual mGlu2/3 receptor agonist activity. We have now further explored this structure-activity relationship through the preparation of cyclic and acyclic C4-disubstituted analogs of 1, leading to the identification of C4-spirocyclopropane 5 (LY2934747), a novel, potent, and systemically bioavailable mGlu2/3 receptor agonist which exhibits both antipsychotic and analgesic properties in vivo. In addition, through the combined use of protein-ligand X-ray crystallography employing recombinant human mGlu2/3 receptor amino terminal domains, molecular modeling, and site-directed mutagenesis, a molecular basis for the observed pharmacological profile of compound 2 is proposed.
Subject(s)
Bridged Bicyclo Compounds/pharmacology , Receptors, Metabotropic Glutamate/agonists , Spiro Compounds/pharmacology , Animals , Bridged Bicyclo Compounds/chemistry , Bridged Bicyclo Compounds/metabolism , Crystallography, X-Ray , Humans , Male , Models, Molecular , Protein Structure, Tertiary , Rats , Rats, Sprague-Dawley , Receptors, Metabotropic Glutamate/chemistry , Receptors, Metabotropic Glutamate/genetics , Spiro Compounds/chemistry , Spiro Compounds/metabolismABSTRACT
The transformation of a simple disubstituted pyridine into a pyridinium ion bearing an exocyclic hydroxyl group, protected as a silane, enabled an intramolecular hydride transfer reaction to take place when fluoride was used as a nucleophile. The addition was both regio- and stereoselective and enabled the formation of enantiopure dihydropyridones when enantiopure pyridine derivatives were used in this sequence. The heterocyclic products contain ample functionality for further elaboration reactions and subsequent derivatization.
Subject(s)
Pyridinium Compounds/chemistry , Pyridones/chemical synthesis , Hydrogenation , Models, Molecular , Molecular Structure , StereoisomerismABSTRACT
The regioselective addition of nucleophiles to pyridinium salts generates an intermediate enol-ether, which can be hydrolyzed in situ to provide a range of dihydropyridones. Certain Grignards have shown inherent differences in the regioselectivity of addition to these salts, and this difference can be tuned to give single regioisomeric addition products. The dihydropyridone products can be further manipulated in many ways using standard transformations.
