Discovery of AMG 193, an MTA-Cooperative PRMT5 Inhibitor for the Treatment of -Deleted Cancers.

deletion occurs in 10-15% of all human cancers due to its proximity to the tumor suppressor gene . The loss of MTAP leads to accumulation of methylthioadenosine (MTA), which shares structural similarity to -adenosyl methionine (SAM), the methyl donor for the cell-essential protein arginine methyltransferase 5 (PRMT5). By competing with SAM, MTA partially inhibits PRMT5, making -deleted tumors susceptible to further PRMT5 inhibition.

Identification of Structurally Novel KRAS Inhibitors through Covalent DNA-Encoded Library Screening.

Covalent inhibition of the KRAS oncoprotein has emerged as a promising therapeutic approach for the treatment of nonsmall cell lung cancer (NSCLC). The identification of KRAS inhibitors has typically relied on the high-throughput screening (HTS) of libraries of cysteine-reactive small molecules or on the attachment of cysteine-reactive warheads to noncovalent binders of KRAS. Such screening approaches have historically been limited in the size and diversity of molecules that could be effectively screened.

Callyspongiolide Is a Potent Inhibitor of the Vacuolar ATPase.

Callyspongiolide is a marine-derived macrolide that kills cells in a caspase-independent manner. NCI COMPARE analysis of human tumor cell line toxicity data for synthetic callyspongiolide indicated that its pattern of cytotoxicity correlated with that seen for concanamycin A, an inhibitor of the vacuolar-type H-ATPase (V-ATPase). Using yeast as a model system, we report that treatment with synthetic callyspongiolide phenocopied a loss of V-ATPase activity including (1) inability to grow on a nonfermentable carbon source, (2) rescue of cell growth via supplementation with Fe, (3) pH-sensitive growth, and (4) a vacuolar acidification defect visualized using the fluorescent dye quinacrine.

Assembly of Complex Macrocycles by Incrementally Amalgamating Unprotected Peptides with a Designed Four-Armed Insert.

We describe the asymmetric synthesis of a highly substituted ω-octynoic acid derivative and demonstrate its utility for generating complex macrocycles from unprotected peptides. The molecule harbors an isolated quaternary center that displays four uniquely functionalized arms, each of which can be reacted orthogonally in sequence as the molecule is integrated into peptide structure. These processing sequences entail (1) scaffold ligation, (2) macrocyclization via internal aromatic alkylations or catalyzed etherifications, (3) acyliminium ion mediated embedding of condensed heterocycles, and (4) terminal alkyne derivatization or dimerization reactions.

Unconventional Fragment Usage Enables a Concise Total Synthesis of (-)-Callyspongiolide.

An asymmetric synthesis of (-)-callyspongiolide is described. The route builds the macrolide domain atypically from a disaccharide and a monoterpene without passing through a seco-acid. Chiral iridium catalysis selectively joins fragments.

Exploring the Boundaries of "Practical": De Novo Syntheses of Complex Natural Product-Based Drug Candidates.

This review examines the state of the art in synthesis as it relates to the building of complex architectures on scales sufficient to drive human drug trials. We focus on the relatively few instances in which a natural-product-based development candidate has been manufactured de novo, rather than semisynthetically. This summary provides a view of the strengths and weaknesses of current technologies, provides perspective on what one might consider a practical contribution, and hints at directions the field might take in the future.

Catalytic asymmetric Tamura cycloadditions involving nitroalkenes.

The first examples of asymmetric Tamura cycloaddition reactions involving singly activated alkenes are reported. Homophthalic anhydride reacts with α-methyl nitrosytrenes in the presence of an alkaloid-based catalyst to generate fused bicyclic aromatic ketone products with three new stereocentres (which are susceptible to subsequent equilibration) in 12-99% ee. An unusual equilibration process which occurs in methanolic medium in the absence of a recognisable base via proton transfer at the α-carbon of an ester was investigated experimentally and computationally.

The first catalytic asymmetric cycloadditions of imines with an enolisable anhydride.

The first catalytic, asymmetric reactions of imines with homophthalic anhydride to form disubstituted 3,4-dihydroisoquinolones are reported. The use of N-mesyl aldimines is key, as more basic imines undergo rapid uncatalysed reactions, while imines possessing larger N-sulphonyl substituents form lactams with lower ee.

Catalytic formal cycloadditions between anhydrides and ketones: excellent enantio and diastereocontrol, controllable decarboxylation and the formation of adjacent quaternary stereocentres.

It has been shown for the first time that enolisable anhydrides can participate in highly efficient and diastereo/enantioselective additions to activated ketones. In these reactions the anhydride component formally acts (initially) as the nucleophilic component. These processes are promoted by novel, readily prepared urea-substituted cinchona alkaloid-derived catalysts at low loadings under mild conditions.

A practical aryl unit for azlactone dynamic kinetic resolution: orthogonally protected products and a ligation-inspired coupling process.

The first strategy for bringing about enantioselective azlactone dynamic kinetic resolution to generate orthogonally protected amino acids has been developed. In the presence of a C2-symmetric squaramide-based catalyst, benzyl alcohol reacts with novel yet readily prepared tetrachloroisopropoxycarbonyl-substituted azlactones to generate trapped phthalimide products of significant synthetic interest with excellent enantiocontrol. These materials are masked amino acids which are demonstrably orthogonally protected: cleavage of the phthalimide can be achieved in the presence of the ester and vice versa.

Catalytic asymmetric Tamura cycloadditions.

In the presence of a novel, tert-butyl-substituted squaramide-based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products of significant synthetic interest with excellent enantio- and diastereocontrol. The methodology is of wide scope and encompasses both homophthalic and glutaconic anhydride derivatives, which lead to structurally diverse products. Glutaconic acid-derived anhydrides undergo a clean post-cyclization decarboxylation process which is not a feature of reactions involving homophthalic acid-derived anhydrides.

Catalytic, enantio- and diastereoselective synthesis of γ-butyrolactones incorporating quaternary stereocentres.

A new, highly enantio- and diastereoselective catalytic asymmetric formal cycloaddition of aryl succinic anhydrides and aldehydes which generates paraconic acid (γ-butyrolactone) derivatives is reported.

A catalytic asymmetric reaction involving enolizable anhydrides.

In the presence of a highly efficient novel bifunctional organocatalyst at low loadings under mild conditions, enolizable homophthalic anhydrides can be added to a range of aromatic and aliphatic aldehydes to give dihydroisocoumarins, with excellent yields and diastereo- and enantiocontrol (up to 99% ee).