Tetrasubstituted Olefinic Xanthene Dyes: Synthesis via Pd-Catalyzed 6-exo-dig Cyclization/C–H Activation of 2‑Bromobenzyl‑N‑propargylamines and Solid State Fluorescence Properties

Tetrasubstituted olefin based new xanthene derivatives have been synthesized via palladium-catalyzed carbopalladation/C–H activation of 2-bromobenzyl-N-propargylamine derivatives. The synthesized compounds display a pronounced solid state fluorescence due to their restricted internal rotation of a C–Ar bond in the solid or aggregation state.