Vinylogous acyl nonaflates, like the corresponding triflates, are subject to nucleophile-triggered
fragmentation as part of a tandem process for generating functionalized alkynes. Advantages
to the use of nonaflates in lieu of triflates include cost and stability. Computational
analysis supports a postulated fragmentation mechanism involving a closed (cyclic)
transition state with concerted extrusion of lithium sulfonate.
Key words
alkynes - fragmentation - nucleophilic addition - solvent effects - tandem reaction