SNS ligand-assisted catalyst activation in Zn-catalysed carbonyl hydroboration

Ligands that include Lewis acid/base functionality have extensive applications in bifunctional catalysis using first row metals. In this work, zinc bis(amido), bis(thiolate) and amido-thiolate SNS complexes were prepared and compared as precatalysts for carbonyl hydroboration using pinacolborane. Mechanistic studies revealed two different ligand-assisted precatalyst activation pathways, both leading to an active and robust zinc alkoxide catalyst. This work furthers our understanding of metal-ligand cooperation in first-row metal catalysis. Zinc amido and thiolate SNS complexes exhibit distinct ligand-assisted pre-catalyst activation pathways for carbonyl hydroboration using pinacolborane.