Used in Suzuki-Miyaura cross-coupling reactions as a boronic ester reagent for the synthesis of biaryl compounds, particularly in medicinal chemistry for constructing nitrogen-containing heterocyclic scaffolds. Its 7-azaindole core is valuable in drug discovery, especially in kinase inhibitor development. The phenylsulfonyl group acts as a protecting or directing moiety, enhancing stability and selectivity during coupling. Commonly applied in the preparation of pharmaceutical intermediates where controlled functionalization of azaindole systems is required.