Fluorous Synthesis:  Fluorous Protocols for the Ugi and Biginelli Multicomponent Condensations

A new protocol for multicomponent condensation reactions that uses fluorous (highly fluorinated) substrates is introduced. This method takes advantage of the ease of purification of fluorous compounds by liquid−liquid extractions between fluorous and organic solvents. The application of this method to the Ugi and Biginelli reactions is described. The condensation products of these two reactions, amino acid amides and dihydropyrimidines, are easily obtained without chromatography in high purities, even though the other reagents are used in very large excesses. This is the first demonstration of the suitability of fluorous phase methods for combinatorial synthesis of “druglike” organic molecules.