New phenanthridine linkers for the solid-phase synthesis of acid-containing compounds

Two novel, reusable phenanthridine linkers that use cerium ammonium nitrate as a cleavage reagent are described. These linkers are based on a disubstituted amide and are designed for the release of carboxylic acids but tolerate exposure to acidic, basic, and reductive reaction conditions. Application of these linkers to solid-phase organic synthesis affords products in excellent yields and high purities.