Copper-/Silver-Mediated Arylation of C(sp²)–H Bonds with 2-Thiophenecarboxylic Acids

Abstract

A copper/silver-mediated arylation of (hetero)aryl C-H bonds with 2-thiophenecarboxylic acids has been achieved. The protocol features a broad substrate scope and high functional group tolerance. Preliminary mechanistic studies indicate that a cascade protodecarboxylation/dehydrogenative coupling process is likely involved.

Copper‐Mediated Decarboxylative Coupling of Benzamides with ortho‐Nitrobenzoic Acids by Directed C−H Cleavage

“…Moreover,d ecarboxylative couplings combined with transition-metal-mediated CÀHactivation, namely decarboxylative CÀHfunctionalization have also been developed. [1,[5][6][7][8][9][10] These reactions have received significant attention because of their higher synthetic efficiency compared to the traditional cross-coupling technologies with organic halides and organometallic reagents.I np articular, arenes bearing ar elatively acidic CÀHb ond, such as azoles [6] and perfluoroarenes, [7] or highly electron-rich heteroarenes,s uch as indoles [8] and thiophenes, [9] can be coupled with benzoic acids to produce biaryl skeletons.T hese reactions are very convenient and powerful methods to synthesize biaryl compounds.I nc ontrast, few examples of decarboxylative arylation by directed C À Hc leavage have been reported to date, [10] although an umber of regioselective CÀHt ransformation reactions are available. [11] Moreover,n oble-transition-metal catalysts such as palladium are essential in most cases.T here are two reports of copper-mediated decarboxylative C À Ha rylation, but viable substrates are still limited to either 1,3-azoles [6c] or 2-thiophenecarboxylic acids.…”

Ruthenium(II)‐Catalyzed C−C Arylations and Alkylations: Decarbamoylative C−C Functionalizations

“…[1] In sharp contrast, selective functionalizations of otherwise inert CÀC s-bonds continue to be scarce, [2] with notable recent progress achieved by ruthenium(II) catalysis. Within our ongoing program on ruthenium(II)-catalyzed [5] stepeconomical diversifications, [6] we have identified reaction conditions for the first ruthenium-catalyzed [7] decarbamoylative C À Cf unctionalization, on which we report herein. Within our ongoing program on ruthenium(II)-catalyzed [5] stepeconomical diversifications, [6] we have identified reaction conditions for the first ruthenium-catalyzed [7] decarbamoylative C À Cf unctionalization, on which we report herein.…”

“…[3] In spite of undisputable advances,r uthenium-catalyzed C À C activations are thus far largely restricted to decarboxylation [4] manifolds being devoid of ipso-CÀCfunctionalization. Within our ongoing program on ruthenium(II)-catalyzed [5] stepeconomical diversifications, [6] we have identified reaction conditions for the first ruthenium-catalyzed [7] decarbamoylative C À Cf unctionalization, on which we report herein. Notable features of our findings are not limited to 1) versatile ruthenium(II)-catalyzed decarbamoylative CÀCa rylations, 2) expedient CÀCa rylations and CÀCa lkylations on modifiable [8] pyrazoles,a sw ell as 3) detailed mechanistic insights into organometallic C À Ccleavage reactions ( Figure 1).…”

Aerobic copper-catalyzed decarboxylative thiolation

“…21 This key result also eliminated the possibility of a tandem prodecarboxylation/C−H thiolation reaction pathway. 22 The 2--methylsulfonyl benzoic acid participated well In the reaction (3q), suggesting the possibility of replacing the ortho--nitro group with other eletron--withdrawing and chelating substituents.…”