Identification of MRTX1133, a Noncovalent, Potent, and Selective KRAS Inhibitor.

KRAS, the most common oncogenic KRAS mutation, is a promising target for the treatment of solid tumors. However, when compared to KRAS, selective inhibition of KRAS presents a significant challenge due to the requirement of inhibitors to bind KRAS with high enough affinity to obviate the need for covalent interactions with the mutant KRAS protein. Here, we report the discovery and characterization of the first noncovalent, potent, and selective KRAS inhibitor, MRTX1133, which was discovered through an extensive structure-based activity improvement and shown to be efficacious in a KRAS mutant xenograft mouse tumor model.

Controlled Cationic Polymerization: Single-Component Initiation under Ambient Conditions.

Cationic polymerizations provide a valuable strategy for preparing macromolecules with excellent control but are inherently sensitive to impurities and commonly require rigorous reagent purification, low temperatures, and strictly anhydrous reaction conditions. By using pentacarbomethoxycyclopentadiene (PCCP) as the single-component initiating organic acid, we found that a diverse library of vinyl ethers can be controllably polymerized under ambient conditions. Additionally, excellent chain-end fidelity is maintained even without rigorous monomer purification.

A Scalable, One-Pot Synthesis of 1,2,3,4,5-Pentacarbomethoxycyclopentadiene.

1,2,3,4,5-Pentacarbomethoxycyclopentadiene (PCCP) is a strong organic acid and a precursor to useful organocatalysts, including chiral Brønsted acids and silicon-based Lewis acids. The synthetic route to PCCP, first reported in 1942, is inconvenient for a number of reasons. The two-step synthesis requires the purification of intermediates from intractable side-products, high reaction temperatures, and extensive labor (3 days).