Copper(I)‐Catalyzed Regioselective Monoborylation of 1,3‐Enynes with an Internal Triple Bond: Selective Synthesis of 1,3‐Dienylboronates and 3‐Alkynylboronates

Hooray for hydroboration! The products afforded by the title reaction depend on the substitution pattern on the double bond moiety of 1,3-enyne substrates (see scheme). These types of products, either 1,3-dienylboronates or 3-alkynylboronates, are difficult to obtain by other methods. Interestingly, ligand-controlled borylation was observed with high selectivity in some cases. pin=pinacolato, THF=tetrahydrofuran.