The Synthesis of Enantiopure α-Fluoro and α,α-Difluoro-β3-Arginine Derivatives

Abstract

The synthesis of a set of monofluorinated, difluorinated, and non-fluorinated N-acetylated-β3-arginine esters, potential inhibitors of trypsin-like proteases, is described. Elaboration to the target compounds from previously reported enantiopure precursors derived from 3-hydroxypropanal involved 6–7 steps and was achieved in 48–65 % overall yield. The α,α-difluoro-β3-arginine derivative was found to be particularly prone to hydrolysis. Three β3-arginine derivatives were tested for their ability to inhibit trypsin, the α,α-difluoro compound being assayed in the form of a carboxylate zwitterion.

The Chemistry of Guanidine, Guanidinium, and Guanidinate Compounds

“…[4][5][6][7][8] The active sites of many enzymes contain the amino acid arginine and new derivatives of this compound continue to be developed. [9] Due to its high pK a value, arginine's side chain remains protonated over a wide pH range, including at physiological pH. It is well known for interacting with anionic groups such as phosphates, nucleotide bases, and carboxylatecontaining biomolecules through hydrogen bonding.…”