Solid-Phase Horner−Emmons Synthesis of Olefins

The Horner−Emmons condensation reaction is an attractive and versatile method to generate carbon−carbon bonds, producing olefins as products. Herein is described a study using 3 different resin bound phosphonates and 16 diverse aldehydes. To facilitate the study and to demonstrate the usefulness of this reaction for library synthesis, the protocol was semiautomated. Weighing and sample concentration were performed using the Zymark Benchmate II and Turbovap workstations, respectively. Horner−Emmons synthesis and trifluoroacetic acid cleavage from the resin were performed on a Tecan Combitec synthesis robot. The results from this study define the scope of this useful reaction for chemical library synthesis.