Synthesis of 3,5-diaryl-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY(R)) dyes (pg 1276, 1998)

2-Aryl pyrroles 2 were formed via Suzuki coupling of arylboronic acids to N -BOC protected 2-bromopyrrole. These pyrroles were used to produce 3,5-diar yl BODIPY(R) dyes 1 having red-shifted fluorescence maxima relative to comp arable alkyl-substituted systems. Absorption and fluorescence spectra of th e compounds 1 are discussed. 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacenes(1) are highly fluorescent materials(2) that have a range of applications in s uch areas as biological labeling and syntheses of molecular devices.(3) Sev eral of these dyes are marketed as "BODIPY(R) dyes", e.g. D-2190 (Molecular Probes Inc., Eugene, Oregon, USA). However, they are sold in small quantit ies for biological experiments, but amounts typically required for syntheti c applications would be prohibitively expensive.