Paracyclophanes in Action: Asymmetric Catalytic Dialkylzinc Addition to Imines Using [2.2]Paracyclophane-based N,O-Ligands as Catalysts
作者:Stefan Dahmen、Stefan Bräse
DOI:10.1002/ijch.201100078
日期:2012.2
The asymmetricaddition of dibutylzinc to imines is achieved by employing [2.2]paracyclophane‐based ketimine ligands with good to excellent enantioselectivities. A comparison to other organozinc reagent is made.
Catalytic Enantioselective Addition of Organometallic Reagents to <i>N</i>-Formylimines Using Monodentate Phosphoramidite Ligands
作者:Maria Gabriella Pizzuti、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1021/jo702140f
日期:2008.2.1
The asymmetricsynthesis of protected amines via the copper/phosphoramidite-catalyzed addition of organozinc and organoaluminum reagents to N-acylimines, generated in situ from aromatic and aliphatic α-amidosulfones, is reported. High yields of optically active N-formyl-protected amines and enantioselectivities up to 99% were obtained. Under the reaction conditions, partial oxidation of the phosphoramidite
The base-free van Leusen reaction of cyclic imines on water: synthesis of <i>N</i>-fused imidazo 6,11-dihydro β-carboline derivatives
作者:Killari Satyam、V. Murugesh、Surisetti Suresh
DOI:10.1039/c9ob00660e
日期:——
imidazoles has been demonstrated on water under base-free conditions. The reaction of dihydro β-carboline imines and p-toluenesulfonylmethyl isocyanides furnished the corresponding substituted N-fused imidazo 6,11-dihydro β-carboline derivatives in very good yields under ambient conditions. The use of deuteriumoxide (D2O) as a solvent enabled the incorporation of deuterium isotopes in the imidazole ring
Oxidation of α-amidoaryl sulfones with m-chloroperoxybenzoic acid under mild conditions readily provides the corresponding imides in satisfactory yields. The overall process probably involves formation of an N-acyliminium ion intermediate, which by attack of the peroxyacid anion generates the final imidoderivatives.
malonates to in situ generated N-formylimines of aromatic aldehydes was achieved underphase-transfercatalysis using Cinchona alkaloids-derived quaternaryammoniumsalts. The resulting β-formamidomalonates have been efficiently converted into β-aryl-β-isocyano esters. Their utility in the multicomponent Ugi reaction with chiral cyclic imines has been demonstrated.