Synthesis of Mono-<i>N</i>
-sulfonylimidazolidines by a 1,3-Dipolar Cycloaddition Strategy, as an Alternative to Selective <i>N</i>
-Sulfonylation, and Their Ring Cleavage To Afford 1,2-Diamines
作者:Joydev K. Laha、Krupal P. Jethava、K. S. Satyanarayana Tummalapalli、Sheetal Sharma
DOI:10.1002/ejoc.201700654
日期:2017.8.24
access to mono N-sulfonyl imidazolidines. The improved reactivity of N-sulfonyl imines as dipolarophiles towards azomethine ylides largely eliminated possible Michael addition and favored 1,3-dipolar cycloaddition. Our approach could complement the commonly practiced protection strategy of imidazolidines. Furthermore, nucleophile dependent ring cleavage of N-sulfonyl imidazolidines produced synthetically
已开发出非稳定的甲亚甲酰亚胺与N-磺酰基亚胺的1,3-偶极环加成反应,为单N-磺酰基咪唑烷提供了可行的途径。N-磺酰基亚胺作为偶极亲和剂对偶氮甲亚胺的反应性提高,很大程度上消除了可能的迈克尔加成反应,并促进了1,3-偶极环加成反应。我们的方法可以补充咪唑烷的常用保护策略。此外,N-磺酰基咪唑烷的亲核试剂依赖性环裂解产生了合成上有用的单N-磺酰基1,2-二胺,否则难以获得。通过TBAF处理产生伴随有CH 2挤出的环裂解,产生单N-磺酰基1,2-二胺,而N-磺酰基1,2-二胺的甲基衍生物通过与LAH反应而产生。