Fig. 1. Kinetic profiles of the formation of B₁ using various catalytic systems. [a] Reactions were carried out in a J-Young NMR tube at RT under an argon atmosphere using a 1 : 1 mixture (0.45 mmol) of p-tolylacetylene and pinacolborane in 1 mL of C₆D₆. [b] 2.5 mol% of F and 5 mol% Et₃N; no trace of B₁ was observed, instead D₁ was obtained quantitatively. [c] 2.5 mol% of F, Et₃N and Et₃NH·OTf. [d] 2.5 mol% of A, 3.75 mol% Et₃N and 1.25 mol% Et₃NH·OTf. [e] 2.5 mol% of L₁CuOTf and 5 mol% of Et₃N.