作者:Parminder Kaur、Walter Wever、Suresh Pindi、Raizada Milles、Peng Gu、Min Shi、Guigen Li
DOI:10.1039/c1gc15029d
日期:——
Chiral N-phosphonyl imines were found to be efficient electrophiles for reaction with diethylaluminium cyanide, a non-volatile and inexpensive cyanide source. The reaction produced chiral Strecker adducts, α-aminonitriles, in excellent chemical yields (94–98%) and diastereoselectivities (95 : 5 to >99%). This synthesis was confirmed to follow the GAP chemistry (group-assistant-purification chemistry) process, which can avoid traditional chromatography and recrystallization purifications, i.e., the pure chiral α-aminonitriles bearing a chiral N-phosphonyl group can be simply obtained by washing the solid crude products with hexane. The chiral N-phosphonyl auxiliary can be easily cleaved under mildly acidic conditions and quantitatively recycled by a one-time extraction with n-butanol.
研究发现,手性 N-膦酰亚胺是与氰化二乙基铝(一种非挥发性的廉价氰化物来源)反应的高效亲电体。反应生成了手性 Strecker 加合物--α-氨基硝酰胺,化学收率(94-98%)和非对映选择性(95:5->99%)都非常好。经证实,该合成采用了 GAP 化学(基团辅助纯化化学)工艺,可避免传统的色谱法和重结晶纯化,即只需用正己烷洗涤固体粗产物,即可获得带有手性 N-膦酰基的纯手性 α-氨基硝酸酯。手性 N-膦酰基助剂可在弱酸性条件下轻松裂解,并通过正丁醇一次性萃取定量回收。