Catalyst-Free Regioselective Hydrostannation of Arynes

Abstract

We report the first regioselective hydrostannation of an aryne. Excellent yields were achieved under mild room temperature conditions without the use of additives or catalysts. Preliminary investigations into the effects of substituents have been conducted, revealing impressive levels of regiochemical control. The method also offers a unique route to access 1,2-deuterated arylstannanes demonstrating the power and potential of this chemistry.Arynes are versatile reactive intermediates that participate in many reactions including cycloadditions, 1 nucleophilic additions 2 and electrophile trappings. 3 Transition-metal complex catalysed transformations of arynes have emerged as attractive routes to substituted arenes that are not easily accessible by conventional methods. 4 For example, studies of palladium-catalysed aryne trimerisation, 5 annulation 6 and co-cyclisations of arynes with alkynes, 7 have opened up many new possibilities in synthesis. 8 Transition-metal-catalysed insertion reactions with transient aryne intermediates were first reported by Yoshida and co-workers. In their pioneering studies, efficient palladium-mediated carbostannylations were achieved under mild conditions with a range of organostannanes. 9