223769-22-0Relevant articles and documents
CAL-B-mediated efficient synthesis of a set of valuable amides by direct amidation of phenoxy- and aryl-propionic acids
Benamara, Nourelhouda,Merabet-Khelassi, Mounia,Aribi-Zouioueche, Louisa,Riant, Olivier
, p. 4045 - 4053 (2021)
An efficient, easy and sustainable amidation of a set of non-activated carboxylic acids with anilines, assisted by CAL-B, as biodegradable catalyst, is reported. The enzymatic amidation reactions are performed on set of nonsteroidal anti-inflammatory drugs (NSAIDs), phenoxypropionic acid and protected-prolines by direct condensation of one equivalent of carboxylic acids and two equivalents of anilines derivatives in heptane after 72?h of reaction at 80?°C. The obtained carboxylic amides are recovered with isolated chemical yields varied between moderate and excellent. Fourteen from them are reported for the first time, and an X-ray crystal is obtained for: N-(4-iodophenyl)-2-(4-isobutylphenyl)propanamide 1d.
The stability of imidazolidinones is the primary influence on the catalytic activity of proline amides and proline sulfonamides in enamine catalysis using alkyl aldehyde substrates
Tin, Sergey,Fuentes, Jose A.,Lebl, Tomas,Clarke, Matthew L.
, p. 141 - 147 (2013)
Some N-substituted proline derivatives catalyse the reactions of alkyl aldehydes with electrophilic partners, and others give negligible amounts of product. The key reaction between the aldehyde and the proline derivative has been studied, and a rationale for the reactivity observed is presented. Simple proline amides derived from aromatic amines (poor catalysts) form stable imidazolidinones quite rapidly at the expense of enamines, the latter being detected, if at all, for less than an hour. Less basic proline amides form a kinetic diastereomer of an imidazolidinone that very slowly inverts its stereochemistry to give a final thermodynamic product. The stereochemistry of these diastereomers was fully assigned by 1H NMR, NOE, and TOCSY experiments. A proline amide derived from an alkylamine (good catalyst) forms high concentrations of enamine that is only slowly (days) converted into a single diastereomer of an inert imidazolidinone. In contrast, another good catalyst, a proline sulfonamide, immediately forms a reactive imidazolidinone, that rapidly ring-opens and exchanges with other aldehydes. This presumably drip-feeds iminium ions and enamines into the catalytic cycle. Thus, there are two quite different mechanistic regimes that lead to efficient catalysis. These mechanistic insights should now allow some element of rational design of prolinamides for enamine reactions using aldehydes. Some proline amides are poor catalysts when aldehydes are used as substrates since the catalysts irreversibly form imidazolidinones. Proline amides with more basic amide groups form long-lived enamines, which allows catalysis to proceed. Proline sulfonamides only form imidazolidones, but these are unstable. Copyright
Enantioselective synthesis of binaphthol derivatives by oxidative coupling of naphthol derivatives catalyzed by chiral diamine-copper complexes
Nakajima, Makoto,Miyoshi, Irie,Kanayama, Kumiko,Hashimoto, Shun-Ichi,Noji, Masahiro,Koga, Kenji
, p. 2264 - 2271 (2007/10/03)
A highly efficient process of aerobic oxidative coupling of 2-naphthol derivatives catalyzed by 1 mol % of Cu(OH)Cl·TMEDA has been developed. Enantioselective oxidative coupling of naphthols was achieved by the use of 10 mol % of chiral catalysts prepared from proline-derived diamines and cuprous chloride, affording the corresponding binaphthols in good enantioselectivities of up to 78% ee. The ester moiety at the 3-position of the substrate was found to be essential for the good asymmetric induction observed in the present coupling reaction.
