Fig. 8: The regioselectivity and chemical selectivity control mechanism.

A Regioselective insertion of C≡C triple bond of 1 in Condition A and B; B Regioselective insertion of C=C double bond of 102 in Condition A and B; C Deborylation of 3 in Condition A; D Deborylation of 3 and 4 in Condition B.