Selective addition of amines to 5-trifluoromethyl-2,4-dichloropyrimidine induced by Lewis acids

Cu(II)/PTABS-Promoted, Regioselective SNAr Amination of Polychlorinated Pyrimidines with Mechanistic Understanding

Regioselective amination of polyhalogenated heteroarenes (especially pyrimidines) has extensive synthetic and commercial relevance for drug synthesis applications but is plagued by the lack of effective synthetic strategies. Herein, we report the Cu(II)/PTABS-promoted highly regioselective nucleophilic aromatic substitution (S_NAr) of polychlorinated pyrimidines assisted by DFT predictions of the bond dissociation energies of different C-Cl bonds. The unique reactivity of Cu(II)-PTABS has been attributed to the coordination/activation mechanism that has been known to operate in these reactions, but further insights into the catalytic species have also been provided.

Synthesis of 2,4-diarylated pyrimidines enabled by Ni-catalyzed C–sulfone bond activation

The readily available pyrimidinyl sulfones, in which the C–S bond is cleaved selectively, could serve as electrophiles in the Ni-catalyzed cross-coupling reactions to prepare 2,4-diarylated pyrimidines under mild conditions with a broad scope.

Design, synthesis, and biological evaluation of novel covalent inhibitors targeting focal adhesion kinase

Forty-one new focal adhesion kinase (FAK) covalent inhibitors were designed and synthesized based on FAK inhibitor TAE226. Compound 11w displayed the highest inhibition of FAK with an IC₅₀ value of 35 nM and exhibited potent anticancer activity against Hela, HCT116 and MDA-MB-231 cell lines with IC₅₀ values of 0.41, 0.01 and 0.11 μM respectively, compared to TAE226 (2.68, 0.64 and 4.19 μM respectively). 11w also inhibited the clone formation and migration of HCT-116 cells and stimulated cell cycle arrest in the G₂/M phase, inducing tumor cell apoptosis. Compound 11w formed a covalent bond with the Cys427 residue of FAK in a docking model, inhibiting the autophosphorylation of FAK and downstream proteins in a dose-dependent manner. Moreover, 11w showed adequate oral bioavailability of 21.02%. A 74.20% inhibition of tumor growth in the HCT116 xenograft model was also observed. These data indicate that 11w is a promising covalent inhibitor of FAK.

Design, Synthesis, and Biological Evaluation of Covalent Inhibitors of Focal Adhesion Kinase (FAK) against Human Malignant Glioblastoma

Human malignant glioblastoma (GBM) is a highly invasive and lethal brain tumor. Targeting of integrin downstream signaling mediators in GBM such as focal adhesion kinase (FAK) seems reasonable and recently demonstrated promising results in early clinical studies. Herein, we report the structure-guided development of a series of covalent inhibitors of FAK. These new compounds displayed highly potent inhibitory potency against FAK enzymatic activity with IC₅₀ values in the nanomolar range. Several inhibitors retarded tumor cell growth as assessed by a cell viability assay in multiple human glioblastoma cell lines. They also significantly reduced the rate of U-87 cell migration and delayed the cell cycle progression by stopping cells in the G2/M phase. Furthermore, these inhibitors showed a potent decrease of autophosphorylation of FAK in glioblastoma cells and its downstream effectors Akt and Erk as well as nuclear factor-κB. These data demonstrated that these inhibitors may have the potential to offer a promising new targeted therapy for human glioblastomas.

Discovery of 2,4-diarylaminopyrimidine derivatives bearing dithiocarbamate moiety as novel FAK inhibitors with antitumor and anti-angiogenesis activities

A series of 2,4-diarylaminopyrimidine derivatives containing dithiocarbamate moiety were designed by molecular hybridization strategy and synthesized for screening as inhibitors of focal adhesion kinase (FAK). Most of these compounds exhibit significant antiproliferative activities on human cancer cell lines expressing high levels of FAK at nanomolar concentrations. The compound 14z was identified as the most potent FAK inhibitor among these candidates. 14z has excellent anti-proliferative effect with IC₅₀ values from 0.001 μM to 0.06 μM on HCT116, PC-3, U87-MG and MCF-7 cell lines and relatively less cytotoxicity to a nonmalignant cell line MCF-10A compared with MCF-7 cells (SI value > 10). 14z also exhibits significant FAK inhibitory activity (IC₅₀ = 0.07 nM). In addition, compound 14z causes cell cycle arrest at G2/M and prompted apoptosis in both HCT116 and MCF-7 cells in a dose-dependent manner. Further studies show that compound 14z inhibits migration of MCF-7 and has anti-angiogenesis effect on HUVEC cells.

Regioselective Control of the SNAr Amination of 5-Substituted-2,4-Dichloropyrimidines Using Tertiary Amine Nucleophiles

The SNAr reaction of 2,4-dichloropyrimidines, further substituted with an electron-withdrawing substituent at C-5, has selectivity for substitution at C-4. Here we report that tertiary amine nucleophiles show excellent C-2 selectivity. In situ N-dealkylation of an intermediate gives the product that formally corresponds to the reaction of a secondary amine nucleophile at C-2. This reaction is practical (fast under simple reaction conditions, with good generality for tertiary amine structure and moderate to excellent yields) and significantly expands access to pyrimidine structures.