Chemoselective Intermolecular Cross-Enolate-Type Coupling of Amides
作者:Daniel Kaiser、Christopher J. Teskey、Pauline Adler、Nuno Maulide
DOI:10.1021/jacs.7b08813
日期:2017.11.15
A new approach for the synthesis of 1,4-dicarbonyl compounds is reported. Chemoselective activation of amide carbonyl functionality and subsequent umpolung viaN-oxide addition generates an electrophilic enolonium species that can be coupled with a wide range of nucleophilic enolates. The method conveys broad functional group tolerance on both components, does not suffer from formation of homocoupling
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
Chemo- and Stereoselective Transition-Metal-Free Amination of Amides with Azides
作者:Veronica Tona、Aurélien de la Torre、Mohan Padmanaban、Stefan Ruider、Leticia González、Nuno Maulide
DOI:10.1021/jacs.6b04061
日期:2016.7.13
challenge in organic synthesis. Herein, we present a stereoselective α-amination of amides employing simple azides that proceeds under mild conditions with release of nitrogen gas. The amide is used as the limiting reagent, and through simple variation of the azide pattern, various differently substituted aminated products can be obtained. The reaction is fully chemoselective for amides even in the presence
regioselective synthesis of 1,5-disubstituted tetrazoles has been developed. By means of electrophilic amide activation, and further C–C bond cleavage and rearrangement, a diverse set of functionalized 1,5-DST derivatives were selectively constructed under mild conditions. As showcased in the mechanisms, the chemoselectivity is easily switched by the selection of the starting materials in the reaction.