Catalyst Selection

Catalyst selection determines both the feasibility and the selectivity of many pharmaceutically important transformations, particularly...

Catalyst selection determines both the feasibility and the selectivity of many pharmaceutically important transformations, particularly transition-metal-catalysed cross-coupling reactions (such as palladium-catalysed Suzuki, Buchwald–Hartwig, and Negishi couplings) that have become indispensable tools for constructing the biaryl and carbon–heteroatom bonds prevalent in modern drug structures. Catalyst selection weighs catalytic activity and turnover efficiency, functional-group tolerance (since a candidate substrate frequently bears multiple reactive functional groups that must survive the coupling conditions unaffected), enantioselectivity where a chiral catalyst is required to access a specific stereoisomer, and, at production scale, catalyst cost and the practicality of removing residual metal catalyst to the strict limits specified by ICH Q3D elemental impurity guidance.