A Palladium-Catalyzed Synthesis of Amidines from Aryl Halides

Direct Palladium(II)-Catalyzed Synthesis of Arylamidines from Aryltrifluoroborates

“…Similarly, amidines can also be accessed by nucleophilic amino substitution of thioamides or imidates. 12 There are also Pd(0)-catalyzed three-component methods, 13 and recently, a direct aryne insertion into thioureas was reported. 14 …”

Metal‐Catalyzed Multicomponent Reactions

“…Formation of an iminoacylpalladium(II) halide 130 by insertion of isocyanide to the newly formed arylpalladium complex followed by a transmetallation step afford the ketimine intermediates 131 (Scheme 8.52). Based on this concept, Whitby and co-workers [110] reported an interesting palladium-catalyzed three-component synthesis of aromatic and heteroaromatic amidines 133 starting from unsaturated halides, amines, and t-butylisocyanide (Scheme 8.53). The catalytic cycle for this iminocarbonylative coupling reaction is analogous to the reactions incorporating carbon monoxide-isoelectronic with isocyanides-as the third partner [111].…”

Palladium‐Catalyzed Imidoylative Cyclization of α‐Isocyanoacetamides: Efficient Access to C2‐Diversified Oxazoles

“…The key step of an imidoylative reaction involves migratory insertion of isocyanide into a palladium(II) intermediate, generated either by oxidative addition of organohalides to a Pd 0 species3 or by Pd II ‐catalyzed CH activation 4. Upon nucleophilic substitution and subsequent reductive elimination, the corresponding amidines,3a amides,3b, 4 ketimines,5 imidates, or thioimidates6 have been obtained depending on the nucleophiles used. In addition, palladium‐catalyzed imidoylative cyclization provides a novel strategy to construct various highly functionalized heterocyclic compounds.…”