Unexpected Electrophilic Rearrangements of Amides: A Stereoselective Entry to Challenging Substituted Lactones
作者:Claire Madelaine、Viviana Valerio、Nuno Maulide
DOI:10.1002/anie.200906416
日期:2010.2.22
Surprise, surprise! An unexpected skeletal rearrangement was developed into a chemo‐ and stereoselective synthesis of α‐allyl and allenyl lactones with challenging substitution patterns (see scheme; EWG=electron‐withdrawing group). The generality, unique features, and synthetic potential of this reaction were probed and a mechanism was proposed.
We developed a new transition-metal-free intermolecular Claisenrearrangement process to introduce allyl and allenyl groups into the α position of tertiary amides. In this transformation, amides were activated by trifluoromethanesulfonic anhydride to produce the keteniminium ion intermediates that exhibit strong electrophilic activity. This atom-economical process delivers α position-modified amides
Free Amino Group Transfer via α‐Amination of Native Carbonyls
作者:Minghao Feng、Anthony J. Fernandes、Ana Sirvent、Eleonora Spinozzi、Saad Shaaban、Nuno Maulide
DOI:10.1002/anie.202304990
日期:2023.7.10
An amino group transfer strategy was developed to install free NH2 to the α-position of native carbonyls under mild conditions. The resulting primary α-aminated products are amenable to in situ peptide coupling or Pictet–Spengler cyclization in one-pot procedures. We anticipate this method to provide a general platform towards the synthesis of amines, ultimately opening exciting avenues in the synthesis