Palladium-Catalyzed Perarylation of 3-Thiophene- and 3-Furancarboxylic Acids Accompanied by C−H Bond Cleavage and Decarboxylation

Abstract

3-thiophene- and 3-furancarboxylic acids efficiently undergo perarylation accompanied by cleavage of the three C-H bonds and decarboxylation upon treatment with excess aryl bromides in the presence of a palladium catalyst to give the corresponding tetraarylated products in good yields.

Palladium‐Catalyzed C2 or C5 Direct Arylation of 3‐Formylthiophene Derivatives with Aryl Bromides

“…[4] The polyarylation of 3-thiophenecarboxylic acid has been described by Miura and co-workers. [5] On the other hand, the regiocontrolled direct arylation of 3-substituted thiophenes has attracted less attention. [6][7][8][9][10] In 2003, Sharp and co-workers reported conditions that allow the selective regioselective arylation of methyl 3-thiophene carboxylate.…”

Thiophenes, Thiophene 1,1-Dioxides, and Thiophene 1-Oxides (Update 2011)

“…More recently, several new approaches have been reported. [172] The extrusion of carbon dioxide is also the initiating step in decarboxylative cross-coupling reactions, [171,[173][174][175][176][177] and is thus preparatively valuable. 170 8 8C (Scheme 43).…”

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

“…机理研究表明, 烯醇硅酯在 催化氧化条件下原位生成烯酯, 再参与脱羧 Heck 偶联 反应 [32] ; 由于硝基乙烯易自聚而不能稳定存在, 作者认 为硝基乙烷原位生成硝基乙烯, 从而获得脱羧 Heck 偶 联反应产物 [33] . 除了实现 Pd 催化 β 位五元杂环羧酸脱羧与 ArBr 的偶联反应 [39] 外, Miura 与其合作者 [40,41] 还发展了 Pd 催 化苯并噻吩羧酸或吲哚羧酸脱羧, 与 ArBr 发生偶联反 应. 根据苯并五元杂环羧酸的底物不同, 需使用不同的 膦配体: 对于 2-苯并噻吩甲酸底物, 反应中需使用 2-(二 叔丁基膦)联苯作配体(Eq.…”