The utilization of N-trifluoroacetyl (TFA)-alpha-amino acid N-hydroxysuccinimide ester (OSu) derivatives, a promising acylating agent with high storage stability, is reported for Friedel Crafts acylation into arenes and N-heterocycles. The reaction between TFA-Phe-OSu derivatives and arenes afforded inter- and intramolecular products. TFA-Tyr-OSu derivatives, which possess hydroxyl substituent in the aromatic moiety of phenylalanine, afforded only intermolecular product with benzene. The heterocyclic TFA-Pro-OSu also shows relatively high reactivity toward acylation.
摘要19 FN.mr研究表明N-三氟乙酰基-d-和-l -4-氟苯基丙氨酸和N-三氟乙酰基d-和-l-苯基丙氨酸与环麦芽六糖(α-环糊精)形成1:1包合物,稳定性常数在pH 6.5和25°的0.1 m NaCl水溶液中分别得到11.44±1.13、11.40±1.09、6.15±0.59和6.37±0.81 m -1。在相似的条件下,N-三氟乙酰基-[2 H 8]苯丙氨酸的相关时间从游离态的65±4 ps变为复合物中的320±40 ps,这与客体在物质中的运动自由度很小有关包容性。