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
Borinic Acid Catalysed Reduction of Tertiary Amides with Hydrosilanes: A Mild and Chemoselective Synthesis of Amines
作者:Aurélien Chardon、Tharwat Mohy El Dine、Rémi Legay、Michaël De Paolis、Jacques Rouden、Jérôme Blanchet
DOI:10.1002/chem.201604802
日期:2017.2.10
A reduction of various aryl, alkyl, and α,β‐unsaturated amides with phenylsilane, catalysed by a borinic acid, is reported. The unprecedented reaction was carried out under very mild conditions and led to useful amines. Furthermore, the reaction tolerates a variety of functional groups. Initial investigations implicated that an intermediate diarylhydroborane is involved in the reaction mechanism.
Dual Nucleophilic/Electrophilic Capture of In Situ Generated Iminium Ethers: Towards the Synthesis of Functionalized Amide Building Blocks
作者:Bo Peng、Daniel H. O'Donovan、Igor D. Jurberg、Nuno Maulide
DOI:10.1002/chem.201203293
日期:2012.12.14
linear amides into a diverse range of branched, functionalized products by conversion to iminium esters is followed by sequential treatment with nucleophiles and electrophiles (see scheme). The method takes advantage of a novel Claisen rearrangement and the use of aromatic substrates greatly facilitates the formation of the intermediate iminiumether.