A Versatile Catalyst for Intermolecular Direct Arylation of Indoles with Benzoic Acids as Arylating Reagents

Abstract

Kupferkomplexe zur CO2‐Fixierung: Kupfer(I)‐Komplexe sind ausgezeichnete Katalysatoren für die Carboxylierung von Aryl‐ und Alkenylboronsäureestern mit CO2 unter Bildung funktionalisierter Carbonsäurederivate (siehe Schema). Als wichtige Intermediate wurden ein Aryl‐ und ein Carboxylatkomplex, [(IPr)CuR] bzw. [(IPr)CuOCOR], isoliert und strukturanalytisch charakterisiert. R=4‐MeOC6H4, IPr=1,3‐Bis(2,6‐diisopropylphenyl)imidazol‐2‐yliden.

Visible‐Light‐Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions

“…[9] To date,a romatic decarboxylation has been realized mainly by concerted decarboxylative metalation/functionalization processes as pioneered by Goossen, [10] Larrosa, [11] and Su. [12] These processes are often limited by substrate bias and the requirement for harsh reaction conditions to facilitate the unfavorable direct decarboxylation. Alternatively,SET-mediated reductive [13] or oxidative decarboxylation processes [14] have also been developed for specific cases.H owever, the necessity for astoichiometric oxidant or reductant along with the prerequisite for redox property matching in each electron transfer step can limit the catalyst turnover and the choice of coupling partner.…”

Transition Metal‐Catalyzed CH Activation of Indoles

“…When AcOK was used as base and aryl iodides as coupling partners,C -2 arylation took place in mostly good yields.H owever, when LiOH·H 2 Ow as used as base in the presence of aryl bromides,C-3 arylation was the prevalentcoupling reaction. Thee lectronics of the coupling partner can also be ad ecisivep arameter,a sd escribedbyS ua nd co-workers, [162] (Scheme77). They studied the intermolecular arylation of indoles with benzoica cid, Pd(TFA) 2 , Ag 2 CO 3 in propionic acid andT MSO.C -2 regioselectivity was obtained when the benzoic acids contained electron-donating groups,w hereas high C-3r egioselectivity was observed when the benzoic acids contained electron-withdrawing groups.T wo distinct reaction mechanismsw ere believed to operate depending on the electronics of the benzoic acid.…”

Recent Progress in Pd-Catalyzed Decarboxylative Coupling Reactions of (Hetero)aromatic Carboxylic Acids

“…类似的, 吴劼课题组 [58] Pd-catalyzed intramolecular decarboxylative C-H bond arylation and the relevant mechanism DMSO/1,4-dioxane Tan [64] Su [65] + (13) 对于其它类型的杂环化合物 C-H 键活化参与脱羧 偶联反应的报道, 苏伟平 [67,68] 、 Larrosa [69] , 以及 Greaney…”