Catalytic Enantioselective Protonation of Nitronates Utilizing an Organocatalyst Chiral Only at Sulfur
作者:Kyle L. Kimmel、Jimmie D. Weaver、Melissa Lee、Jonathan A. Ellman
DOI:10.1021/ja3026196
日期:2012.6.6
highly enantioselective protonation of nitronates formed upon the addition of α-substituted Meldrum's acids to terminally unsubstituted nitroalkenes is described. This work represents the first enantioselective catalytic addition of any type of nucleophile to this class of nitroalkenes. Moreover, for the successful implementation of this method, a new type of N-sulfinyl urea catalyst with chirality residing
描述了在将 α-取代的 Meldrum 酸添加到末端未取代的硝基烯烃时形成的硝基的高度对映选择性质子化。这项工作代表了任何类型的亲核试剂对此类硝基烯烃的首次对映选择性催化加成。此外,为了成功实施该方法,开发了一种仅在亚磺酰基上具有手性的新型 N-亚磺酰基脲催化剂,从而能够引入多种非手性二胺基序。最后,Meldrum 的酸加成产物很容易以高产率转化为药学相关的 3,5-二取代吡咯烷酮。