Transition Metal-Catalyzed Reactions of Alkynyl Halides.

Background: Transition metal-catalyzed reactions of alkynyl halides are a versatile means of synthesizing a wide array of products. Their use is of particular interest in cycloaddition reactions and in constructing new carbon-carbon and carbon-heteroatom bonds. Transition metal-catalyzed reactions of alkynyl halides have successfully been used in [4+2], [2+2], [2+2+2] and [3+2] cycloaddition reactions.

Cationic Ruthenium-Catalyzed Bis-Homo-Diels-Alder Cycloaddition.

Objective: The ruthenium-catalyzed Bis-Homo-Diels-Alder cycloaddition between 1,5- cyclooctadiene and alkynes was explored, and the use of commercially available cationic catalysts was investigated. It was noted that [CpRu(CH3CN)3]PF6 was effective at catalyzing this cycloaddition and yields of the desired tricyclo[4.2.