Parallel synthesis of tandem Ugi/Diels–Alder reaction products on a soluble polymer support directed toward split-pool realization of a small molecule library

A series of parallel reactions were carried out for the tandem Ugi/Diels–Alder reaction on our MPEG–O–CH2- platform. Ninety-six out of a 100 entries were successful to give complex heterotricycles. The stereoselectivity was found not to be influenced by the building blocks used for amine and carboxylic acid components. An unexpected side pathway was found but was suppressed by employing appropriate reaction conditions. The reaction was also performed on solid phase, by which a larger library is potentially realized by employing the split-pool method.