Broadly Applicable Ion Pair-Assisted Nucleophilic Substitution of sp 3 -Carbon Electrophiles with Alkynyltrifluoroborates.

Alkynyltrifluoroborate nucleophiles react smoothly with a wide range of sp 3 -carbon electrophiles, including propargyl methanesulfonates and unactivated alkyl triflates, to give Sonogashira-type products, via a novel ion pair-assisted nucleophilic substitution mechanism. An ion pair-organic complex, investigated using computational chemistry and in situ NMR experiments, may play a crucial role in this reaction.