Discovery of GLPG1972/S201086, a Potent, Selective, and Orally Bioavailable ADAMTS-5 Inhibitor for the Treatment of Osteoarthritis.

There are currently no approved disease-modifying osteoarthritis (OA) drugs (DMOADs). The aggrecanase ADAMTS-5 is key in the degradation of human aggrecan (AGC), a component of cartilage. Therefore, ADAMTS-5 is a promising target for the identification of DMOADs. We describe the discovery of GLPG1972/S201086, a potent and selective ADAMTS-5 inhibitor obtained by optimization of a promising hydantoin series following an HTS. Biochemical activity against rat and human ADAMTS-5 was assessed via a fluorescence-based assay. ADAMTS-5 inhibitory activity was confirmed with human aggrecan using an AGC ELISA. The most promising compounds were selected based on reduction of glycosaminoglycan release after interleukin-1 stimulation in mouse cartilage explants and led to the discovery of GLPG1972/S201086. The anticatabolic activity was confirmed in mouse cartilage explants (IC50 < 1.5 µM). The cocrystal structure of GLPG1972/S201086 with human recombinant ADAMTS-5 is discussed. GLPG1972/S201086 has been investigated in a phase 2 clinical study in patients with knee OA (NCT03595618).

Conjugate additions to alkylidene bis(sulfoxides).

A general study on the conjugate addition of anionic nucleophiles to alkylidene bis(sulfoxides) is presented. Alkoxides gave high yielding and diastereoselective addition reactions, which could be influenced by solvents and the counteranion. Azides provided an interesting entry into sulfinyl-substituted triazoles. Organometallics, mainly copper reagents, proved also to be valuable nucleophiles, and complete inversion of the stereoselectivity was achieved in the addition reaction with the latter. Modelizations provide a rationale for the observed diastereoselectivity.

Diastereoselective synthesis of enantiopure acyclic beta,beta'-disubstituted vinylsulfoxides.

Thermal elimination of sulfenic acid from enantiopure beta,beta'-disubstituted bis-sulfoxides allows the stereoselective synthesis of enantiopure acyclic beta,beta'-disubstituted vinylsulfoxides. This mild and stereospecific synthesis provides either ( E) or ( Z) vinylsulfoxides in high yields and is compatible with acid or base sensitive functional groups.

Dechalcogenative allylic selenosulfide and disulfide rearrangements: complementary methods for the formation of allylic sulfides in the absence of electrophiles. Scope, limitations, and application to the functionalization of unprotected peptides in aqueous media.

Primary allylic selenosulfates (seleno Bunte salts) and selenocyanates transfer the allylic selenide moiety to thiols giving primary allylic selenosulfides, which undergo rearrangement in the presence of PPh3 with the loss of selenium to give allylically rearranged allyl alkyl sulfides. This rearrangement may be conducted with prenyl-type selenosulfides to give isoprenyl alkyl sulfides. Alkyl secondary and tertiary allylic disulfides, formed by sulfide transfer from allylic heteroaryl disulfides to thiols, undergo desulfurative allylic rearrangement on treatment with PPh3 in methanolic acetonitrile at room temperature. With nerolidyl alkyl disulfides this rearrangement provides an electrophile-free method for the introduction of the farnesyl chain onto thiols. Both rearrangements are compatible with the full range of functionality found in the proteinogenic amino acids, and it is demonstrated that the desulfurative rearrangement functions in aqueous media, enabling the derivatization of unprotected peptides. It is also demonstrated that the allylic disulfide rearrangement can be induced in the absence of phosphine at room temperature by treatment with piperidine, or simply by refluxing in methanol. Under these latter conditions the reaction is also applicable to allyl aryl disulfides, providing allylically rearranged allyl aryl sulfides in good yields.

Highly diastereoselective ionic/radical domino reactions: single electron transfer induced cyclization of bis-sulfoxides.

SET oxidation of bis-sulfinyl anions has enabled the uses of bis-sulfinyl radical as a synthetic equivalent of chiral acyl and methylene radicals involved in tandem reactions leading to the enantioselective construction of various carbo- and heterocyclic derivatives.

Sigmatropic rearrangements as tools for amino acid and peptide modification: application of the allylic sulfur ylide rearrangement to the preparation of neoglycoconjugates and other conjugates.

Reaction of S-allyl cysteine derivatives, generated by the selenocysteine ligation, with rhodium carbenoids, stabilized and unstabilized, enables the attachment of diverse functionality onto cysteine residues. The reaction is successfully applied to the introduction of lipid-like residues, a fluorous alkyl chain, and mono- and disaccharides.

Allylic disulfide rearrangement and desulfurization: mild, electrophile-free thioether formation from thiols.

[reaction: see text] Secondary and tertiary allylic 2-pyridyl and 2-benzothiazolyl disulfides react with thiol groups at room temperature to give secondary and tertiary allyl alkyl disulfides. On the addition of a phosphine, a desulfurative sigmatropic rearrangement takes place at room temperature to give thioethers.