N-(Fmoc-aα-aminoacyl)benzotriazoles: Versatile synthetic reagents from proteinogenic amino acids

Abstract

N-Fmoc-aα-amino acids were smoothly converted into stable, crystalline N-(Fmoc-aα-aminoacyl)benzotriazoles 2a-r (69-90%). Compounds 2b,g reacted with the chiral derivatizing reagent, (+/-)aα- methylbenzylamine (5 or 6), to afford aα-(N-Fmoc-amino)acid amides 3a,b and 4a,b (average yield 72 %) with no detectable racemization.