One pot synthesis of α,α-bis(N-arylamido) lactams via iodide-catalyzed rearrangement of β,β-bis(N-arylamido) cyclic ketene-N,O-acetals
作者:Yingquan Song、William P. Henry、Hondamuni I. De Silva、Guozhong Ye、Charles U. Pittman
DOI:10.1016/j.tetlet.2010.11.148
日期:2011.2
Five and six-membered cyclic ketene-N,O-acetals, generated in situ from 2,3-dimethyl-2-oxazolinium iodide or 2,3-dimethyl-2-oxazinium iodide and triethylamine, reacted with aryl isocyanates in refluxing THF producing α,α-bis(N-arylamido) lactams via the iodide-catalyzed rearrangement of β,β-bis(N-arylamido) cyclic ketene-N,O-acetal intermediates. The cyclic ketene-N,O-acetal generated in situ from
由2,3-二甲基-2-恶唑啉鎓碘化物或2,3-二甲基-2-恶唑鎓碘化物和三乙胺就地生成的五元和六元环状烯酮-N,O-乙缩醛与芳基异氰酸酯反应生成四氢呋喃并回流α,α-双(N-芳酰胺基)内酰胺通过碘化物催化的β,β-双(N-芳酰胺基)环状烯酮-N,O-缩醛中间体的重排。由2,3,4,4-四甲基-2-恶唑啉鎓碘化物原位生成的环状烯酮-N,O-缩醛与异氰酸酯反应生成β,β-双(N-芳酰胺基)环状烯酮-N,O-缩醛,不容易重新排列。C-4处的两个甲基阻碍了碘化物对C-5的亲核攻击,这是重排所必需的。