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
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.
A terphenyl alpha-helix mimeticscaffold recognized to be capable of disrupting protein-protein interactions was structurally morphed into an easily amenable and versatile multicomponent reaction (MCR) backbone. The design, modular in-parallel library synthesis, initial cell based biological data, and preliminary in vitro screening for the disruption of the Bcl-w/Bak protein-protein interaction by