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We report a facile synthesis of 3-amidino indoles from indoles and cyanamides. The reaction is Pd(II)-catalyzed and proceeds via C-H bond activation of the indole in its 3-position followed by a 1,2-addition of the resulting indole-palladium σ-complex to a cyanamide, which provides the corresponding amidine. The preference for 4,5-diazafluoren-9-one (DAF) as the ligand is investigated using DFT calculations, and a plausible reaction pathway is presented.

A novel metal-free microwave-assisted branching cascades strategy for the efficient synthesis of 3,4-dihydroquinazolinone-embedded polyheterocyclic scaffolds is reported. Starting from in situ generated key N-acyliminium ion precursors, 12 distinct and skeletally diverse polycyclic frameworks were accessed in a single step/pot via adjustment of the nucleophile(s) and reaction conditions. Postcascade functionalization of these compounds was also demonstrated, proving the utility of this method in accessing structurally diverse chemical entities.

A fast and convenient synthesis of arylamidines starting from readily available potassium aryltrifluoroborates and cyanamides is reported. The coupling was achieved by Pd(II)-catalysis in a one step 20 min microwave protocol using Pd(O(2)CCF(3)), 6-methyl-2,2'-bipyridyl, TFA, and MeOH, providing the corresponding arylamidines in moderate to excellent yields.

A new and versatile cyclization reaction affording rare 1N-hydroxyindazoles is presented. Treatment of 2-nitrobenzylamines with methanolic sodium hydroxide furnishes 1N-hydroxyindazoles regioselectively and in high yield. The reaction tolerates a range of functional groups and electronic effects.