Synthesis of Fmoc-Protected Arylphenylalanines (Bip Derivatives) via Nonaqueous Suzuki-Miyaura Cross-Coupling Reactions

A one-step synthesis of Fmoc-protected aryl/heteroaryl-substituted phenylalanines (Bip derivatives) using the nonaqueous palladium-catalyzed Suzuki-Miyaura cross-coupling (SMC) reaction of Fmoc-protected bromo- or iodophenylalanines is reported. This protocol allows for the direct formation of a variety of unnatural biaryl-containing amino acids in good to excellent yield, which can be readily used in subsequent Fmoc solid-phase peptide synthesis. The synthetic utility of this method is also demonstrated by the SMC reaction of bromophenylalanine-containing tripeptides.