A simple and efficient palladium-catalyzed three-component domino reaction of bromothiophenes with internal alkynes has been developed to produce benzo[b]thiophenes in moderate to good yields.

The first example of a regioselective β-arylation of benzo[b]thiophenes and thiophenes at room temperature with aryl iodides as coupling partners is reported. This methodology stands out for its operational simplicity: no prefunctionalization of either starting material is required, the reaction is insensitive to air and moisture, and it proceeds at room temperature. The mild conditions afford ...

An efficient and experimentally rapid protocol for the synthesis of hitherto unreported 2,3-dicarboalkoxy-4-aroyl/heteroaroyl/alkanoyl thiophenes has been developed via 1-2 (C-S) and 3-4 (C-C) bond connections promoted by 4-dimethylaminopyridine (DMAP). Optimally, the reaction takes only 3-5 min when β-oxodithioester and dialkyl acetylenedicarboxylate are stirred in DCM at room temperature in t...

A series of 3-allenyl benzo[b]thiophenes were synthesized through a gold(I)-catalyzed domino reaction. The process consists in 5-endo-dig cyclization with C−S bond formation and consecutive S-to-C propargyl migration via [3,3]-sigmatropic Claisen rearrangement. With aryl substituents on both triple bonds the substrate, subsequent intramolecular hydroarylation formed allenyl system led to 3-inde...

A novel copper(i)-catalyzed tandem addition/cycloisomerization reaction of 1-phenylsulfonylalkylidenethiiranes with terminal alkynes for the convergent assembly of 2-(alpha-phenylsulfonylalkyl)-thiophenes is reported, which could directly assemble various functional groups incorporated into the thiophene ring.

The bulky 2,5-dimethylthiophene (2,5-Me2T) reacts at 60 degrees C with TpMe2Ir(C2H4)2 to give a mixture of two TpMe2Ir(III) hydride products, 3 and 4, that contain in addition a thienyl (3) or a thienyl-derived ligand (4). For the generation of 3 only sp2 C-H activation is needed, but the formation of 4 requires also the activation of an sp3 C-H bond and the formation of a new C-C bond (between...

The addition of heteroaryllithium to various ketones followed by dehydration gave 1-(2-heteroaryl)cycloalkenes and (2-hetero- aryl)alkenes. When alkenes were treated with 10 mol% NIS, calix[4]thiophenes and calix[4]furans were obtained in good yields.

The one-pot conversion of thioenols into benzo[b]thiophenes was achieved by using a simple palladium catalyst such as PdCl(2) or PdCl(2)(cod).