Asymmetric Henry reaction catalyzed by chiral secondary diamine-copper(II) complexes

Chiral Cu(II) Complexes as Recyclable Catalysts for Asymmetric Nitroaldol (Henry) Reaction in Ionic Liquids as Greener Reaction Media

“…The result showed a decrease in product yield (40%) however the enantioselectivity (ee, 84%) was retained (entry 14). This result is in consonance with the earlier report [75]. The blank experiment conducted in the absence of chiral ligand 1 0 keeping other conditions as per entry 13 yielded 52% racemic nitroalcohol (entry 15) indicates that copper metal is active for nitroaldol reaction but to impart enantioselctivity in the product a chiral ligand is essential.…”

“…The organic layer was dried over anhydrous sodium sulphate and evaporated to get the desired product as viscous solid. The characterization of the ligands was accomplished by different physicochemical methods, which matched well with the earlier reports [46,48,75]. …”

“…1) were synthesized by the modified reported procedure [46,48,75]. In a 100 mL round bottom flask aldehyde/substituted aldehydes (1 mmol) was taken in ethanol (20 mL), to which (1S, 2S)-(?…”

Diastereoselective synthesis of tetraalkyl (R,R)-1,2-cyclohexylene-diamino-di-phosphonates bearing thiophene, furan and pyrrole moieties. Computational and experimental study on their formation

“…Complexes of those compounds have been applied in catalysis of the Strecker 1 synthesis of amino acids, or the Kabachnik-Fields reaction 2 as well as in the asymmetric Henry reaction. 3 Some interesting modifications of typical salen imines have been also made to provide salen-based urea and thiourea ligands 3e6 or saturated catalysts originating from salen ligands, 7e9 that resulted in promising applications in catalysis of e.g., the asymmetric Henry reaction. 7,9 Interestingly, applications of salen compounds are not confined to catalysis, since some were found to have particular cytotoxic properties.…”

Chiral 1,1′-binaphthylazepine derived amino alcohol catalyzed asymmetric Henry reaction

“…Amongst them, the copper-containing system is particularly promising due to its ambifunctional character, 14 resulting in high catalytic activity and excellent enantioselectivity especially when in combination with chiral ligands such as bisoxazolines, [15][16][17][18][19][20][21] (À)-sparteine, 22 bisimidazolines, 23,24 diamines, [25][26][27][28][29][30][31][32][33] sulfonyldiamines, [34][35][36] aminopyridines, 37,38 salen [39][40][41][42][43][44][45] and N,N 0 -dioxides, 46 etc.…”