2757-10-0Relevant articles and documents
A new nitrogen-to-oxygen phosphoryl migration
Koziara,Zwierzak
, p. 15 - 21 (1999)
The reaction of diethyl N-acetyl-N-methylphosphoramidate 1 with aldehyde in the presence of LDA at -70°C results in the formation of the unstable oxyanion 6 which undergoes intramolecular rearrangement involving migration of a phosphoryl group from nitrogen to oxygen affording an amide anion 8. Subsequent proton transfer in 8 followed by elimination of phosphate anion provides the respective α,β-unsaturated N-methylcarboxamide 4. The formation of considerable amounts of diethyl N-methylphosphoramidate 5 is also always observed.
Manganese Catalyzed Enantioselective Epoxidation of α,β-Unsaturated Amides with H2O2
Ottenbacher, Roman V.,Kurganskiy, Vladimir I.,Talsi, Evgenii P.,Bryliakov, Konstantin P.
supporting information, p. 2778 - 2782 (2021/04/29)
Herewith, we report the enantioselective epoxidation of electron-deficient cis- and trans-α,β-unsaturated amides with the environmentally benign oxidant H2O2. The catalysts - manganese complexes with bis-amino-bis-pyridine and structurally related ligands - exhibit reasonably high efficiency (up to 100 TON) and excellent chemo- and enantioselectivity (up to 100% and 99% ee, respectively). Crucially, the cis-enamides epoxidation enantioselectivity and yield are dramatically enhanced by the presence of NH-moiety, which effect can be explained by the hydrogen bonding interaction between the cis-enamide substrate and the manganese based oxygen transferring species. (Figure presented.).
Catalytic, transition-metal-free semireduction of propiolamide derivatives: Scope and mechanistic investigation
Grams, R. Justin,Garcia, Christopher J.,Szwetkowski, Connor,Santos, Webster L.
supporting information, p. 7013 - 7018 (2020/09/12)
We report a transition-metal-free trans-selective semireduction of alkynes with pinacolborane and catalytic potassium tert-butoxide. A variety of 3-substituted primary and secondary propiolamides, including an analog of FK866, a potent nicotinamide mononucleotide adenyltransferase (NMNAT) inhibitor, are reduced to the corresponding (E)-3-substituted acrylamide derivatives in up to 99% yield with >99:1 E/Z selectivity. Mechanistic studies suggest that an activated Lewis acid-base complex transfers a hydride to the α-carbon followed by rapid protonation in a trans fashion.
