Fig. 3. Control reactions studying the effect of L donor on the Ti-catalyzed [2 + 2 + 1] heterocoupling of 1a-BBN with 2. (A) Reaction with 0 equiv. pyridine. (B) Excess 1a-BBN acts as a pyridine scavenger. (C) Pyridine-bound 1a-BBN-py reacts significantly slower than 1a-BBN. (D) Schematic demonstrating pyridine coordination equilibrium effects.
