Solid-Phase Synthesis of Asymmetric Cyanine Dyes

Cyanine Dyes (CD) are a functional class of organic molecules used in several applications ranging from photography to bioimaging. Most well-known features CDs reside on high molar extinction coefficients up 105 L mol-1cm-1 and the absorption spectra, 500 1000 nm, which can be fine-tuned both by extending length central methylene bridge or modulating terminal heterocycles. In last decades, new synthetic methodologies, namely microwave-assisted solid-phase procedure, have been developed overcome limitation classical protocols. While microwave approach usually reduces exposure time reagents products thermal degradation, methodology allows easier protocols, translated into higher yields simpler purification. present review, comprehensive analysis methods for synthesis asymmetrical is discussed, with critical evaluation difference among currently available solid-state approaches.