Tenora L1, Galeta J1, Řezníčková E2, Kryštof V2, Potáček M1.
J Org Chem. 2016 Dec 2;81(23):11841-11856. Epub 2016 Nov 10.C-H activation of position 3 of a substituted pyrazole ring catalyzed by palladium(II) was straightforward and convenient for arylated or heteroarylated 5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazoles. Moreover, we introduced simple protection of the nitrogen in the pyridin-2-yl directing group, which otherwise does not allow a cross-coupling reaction, by transformation to the N-oxide. Selected final products were reasonably selective ALK5 kinase inhibitors.