Diastereoselective addition of diethyl difluoromethylphosphonate to enantiopure sulfinimines: synthesis of α,α-difluoro-β-aminophosphonates, phosphonic acids, and phosphonamidic acids
作者:Gerd-Volker Röschenthaler、Valery P. Kukhar、Michael Yu. Belik、Kateryna I. Mazurenko、Alexander E. Sorochinsky
DOI:10.1016/j.tet.2006.08.017
日期:2006.10
of diastereomerically pure N-sulfinyl α,α-difluoro-β-aminophosphonates with trifluoroacetic acid in EtOH followed by refluxing with 10 N HCl provided enantiopure α,α-difluoro-β-aminophosphonates and α,α-difluoro-β-aminophosphonic acids. The N-Cbz derivative of (R)-2-amino-1,1-difluoro-2-phenylethylphosphonate was a convenient starting point for the preparation of corresponding difluorophosphonate monoester
将二乙基硫代二氟甲基膦酸酯加到对映体纯的芳族,杂芳族和脂族醛衍生的亚磺酸亚胺中,得到的N-亚磺酰基α,α-二氟-β-氨基膦酸酯通常具有良好的对映选择性,并且产率很高。与苯乙酮衍生的亚磺胺的反应导致形成具有高非对映选择性且仅中等收率的加成产物。两步脱保护,包括在EtOH中用三氟乙酸处理非对映体纯的N-亚磺酰基α,α-二氟-β-氨基膦酸酯,然后与10 N HCl回流,得到对映体纯的α,α-二氟-β-氨基膦酸酯和α,α-二氟-β-氨基膦酸。(R的N -Cbz导数)-2-氨基-1,1-二氟-2-苯基乙基膦酸酯是制备相应的二氟膦酸酯单酯,二氟膦酸和二氟膦酰胺酸的方便起点。在21°C下,二氟膦酰胺酸在pH高于5的水溶液中稳定。