A new silyl linker for reverse-direction solid-phase peptide synthesis

Treatment of a free amino acid ester with CO2 followed by exposure to a chlorosilane-containing polystyrene results in its attachment to the solid support. The newly formed silyl carbamate can be employed to build polypeptides at the carboxyl terminus. Cleavage of the (poly)peptide using aqueous HF in CH3CN leads to its free amine form which is isolated as a Boc derivative. The polymer support can be easily recycled.