Transition-metal-catalyzed addition of heteroatom-hydrogen bonds to alkynes.

Ru(III)-Catalyzed Cyclization of Arene-Alkene Substrates via Intramolecular Electrophilic Hydroarylation

2,3-Disubstituted benzo[b]thiophenes have been prepared in excellent yields via coupling of terminal acetylenes with commercially available o-iodothioanisole in the presence of a palladium catalyst and subsequent electrophilic cyclization of the resulting o-(1-alkynyl)thioanisole derivatives. I2, Br2, NBS, p-O2NC6H4SCl, and PhSeCl have been utilized as electrophiles. Aryl-, vinyl-, and alkyl-substituted terminal acetylenes undergo this coupling and cyclization to produce excellent yields of benzo[b]thiophenes. (Trimethylsilyl)acetylene also undergoes this coupling/cyclization process with I2, NBS, and the sulfur and selenium electrophiles to afford the corresponding 2-(trimethylsilyl)benzo[b]thiophenes. However, cyclization of the silyl-containing thioanisole using Br2 affords 2,3-dibromobenzo[b]thiophene.

Synthesis of 2,3-disubstituted benzo[b]thiophenes via palladium-catalyzed coupling and electrophilic cyclization of terminal acetylenes.

A.L.-P. thanks CSIC for a contract under JAE-doctors program. Financial support by Consolider-Ingenio 2010 (proyecto MULTICAT) and PLE2009 project from MCIINN is also acknowledged.

Similarities and Differences between the “Relativistic” Triad Gold, Platinum, and Mercury in Catalysis

Regiospecific Carbonylative Annulation of Iodophenol Acetates and Acetylenes To Construct the Flavones by a New Catalyst of Palladium−Thiourea−dppp Complex

L. W. Harrison

Papers

Mercury in organic chemistry. XXVI: Synthesis of heterocycles via intramolecular solvomercuration of aryl acetylenes