Pd(OAc)₂/AgOAc Catalytic System Based Bidentate Ligand Directed Regiocontrolled C–H Arylation and Alkylation of the C‐3 Position of Thiophene‐ and Furan‐2‐carboxamides

Abstract

The title procedure is investigated for various educts bearing different ligands at the amide nitrogen.

Palladium(II)-Promoted Directing Group-Enabled Regioselective C-H Arylation of The C-3 Position of 2- or 3-(Aminoalkyl)-Thiophene and Furfurylamine Derivatives

“…When compared to aryl iodides, iodopyridines afforded the corresponding products 7 p and 7 q in poor yields. Notably, we reported a similar trend in our previous paper involving the C−H arylation of furan‐ and thiophene‐2‐carboxamides …”

“…Apart from the directing group‐free direct C−H arylation of the thiophene and furan systems; additionally, the bidentate ligand‐directed regioselective functionalization of the C(3)‐H and C(4)‐H bonds of the thiophene and furan systems have also been reported . In this method, thiophene‐2‐carboxylic acid and furan‐2‐carboxylic acid derivatives were used as the starting materials and several C3‐functionalized furan/thiophene‐2‐carboxamides were synthesized.…”

“…In this method, thiophene‐2‐carboxylic acid and furan‐2‐carboxylic acid derivatives were used as the starting materials and several C3‐functionalized furan/thiophene‐2‐carboxamides were synthesized. In this regard, recently, our group reported the Pd(OAc) 2 /AgOAc catalytic system‐based, bidentate ligand (e. g. 8‐aminoquinoline or 2‐(methylthio)aniline) directed, regioselective C(3)‐H arylation of the thiophene‐2‐carboxylic acid and furan‐2‐carboxylic acid derivatives.…”

Synthesis of Elaborate Benzofuran-2-Carboxamide Derivatives through a Combination of 8-Aminoquinoline Directed C–H Arylation and Transamidation Chemistry

“…In this optimization study, the effects of several reaction parameters on the C-H arylation of 1a with 4-iodoanisole were investigated ( Table 1). The reaction conditions for the first trial experiment were selected based on a C-H functionalization protocol for furans that had previously been reported by Padmavathi et al [82]. When performing the C-H arylation of 1a with 3 equiv.…”

Highlights of aliphatic C(sp3)‐H hydrogen isotope exchange reactions

“…In 2018, Zhao et al developed a palladium‐catalyzed, auxiliary‐supported, selective H/D exchange reaction applying 8‐aminoquinoline as the directing group and D 2 O as deuterium source ( 76→77 ; Scheme 31). A reaction mechanism was postulated according to similar CH‐functionalization references involving C–X or C–C formation via a palladium amide or cyclometallation intermediate 78 . Some ortho ‐deuterated benzoic acids and β‐deuterated valproic acid were obtained on gram scale following removal of the directing group Q …”