Recent Developments in the Applicationof Organometallic Chemistry to Amino AcidSynthesis

摘要

Alkylzinc iodide reagents derived from amino acids are usefulintermediates for the synthesis of non-proteinogenic aminoacids using metal-catalyzed coupling reactions. Dipolaraprotic solvents, specifically dimethylformamide, reduce therate of elimination of β-amino alkylzinc reagents. These 13-elimination reactions can be further suppressed by usingtrifluoroacetyl protection on nitrogen, which reducesintramolecular coordination to zinc, a key requirement in theelimination process. Acidic protons, specifically phenols, aretolerated in Negishi cross coupling reactions of these reagents.