Switching Pathways: Room-Temperature Neutral Solvolysis and Substitution of Amides
作者:Marc Hutchby、Chris E. Houlden、Mairi F. Haddow、Simon N. G. Tyler、Guy C. Lloyd-Jones、Kevin I. Booker-Milburn
DOI:10.1002/anie.201107117
日期:2012.1.9
Stick or twist: By introducing steric hindrance at the nitrogen atom, stable linear amides bearing an electron‐withdrawing α‐substituent (Z=Ar, PhSO2, P(O)(OR)2, CN, or CO2R) can be induced to undergo solvolysis and substitution reactions through an elimination–addition mechanism (see picture). Key to this process is a low barrier to rotation around the amide bond and the α‐substituent Z.
粘连或扭曲:通过在氮原子上引入位阻,可以形成带有吸电子α取代基(Z = Ar,PhSO 2,P(O)(OR)2,CN或CO 2 R)的稳定的线性酰胺。通过消除-加成机理诱导其经历溶剂分解和取代反应(见图)。该过程的关键是绕酰胺键和α取代基Z旋转的低障碍。