Bifunctional oxazoline-thiourea-based organocatalysts were synthesized and applied to the aza-Henryreactions between N-Boc aryl imines and nitromethane in high ee and chemical yields at room temperature.
合成了基于恶唑啉-硫脲的双功能有机催化剂,并将其应用于 N-Boc 芳基亚胺与硝基甲烷之间的 aza-Henry 反应,在室温下具有高 ee 和化学产率。
Bottom-Up Synthesis of Supported Thioureas and Their Use in Enantioselective Solvent-Free Aza-Henry and Michael Additions
作者:José M. Andrés、Noelia de La Cruz、María Valle、Rafael Pedrosa
DOI:10.1002/cplu.201500476
日期:2016.1
Two sets of supported chiral thioureas, which differ in the length of the tether that connects the chiral appendage to the polymer structure and the effective functionalization, have been prepared by copolymerization of styrene, novel styryl thioureas derived from l-valine, and divinylbenzene. The efficiency of these polymeric thioureas has been tested in two different enantioselective transformations
Bifunctional asymmetric phase-transfercatalysts bearing multiple hydrogen-bonding donors have rarely been explored. The first quaternary ammonium type of these catalysts derived from cinchona alkaloids were readily prepared and found to be highly efficient catalysts for asymmetric nitro-Mannichreactions of amidosulfones. Compared with previous reports, very broad substrate generality was observed
Chiral Proton Catalysis: A Catalytic Enantioselective Direct Aza-Henry Reaction
作者:Benjamin M. Nugent、Ryan A. Yoder、Jeffrey N. Johnston
DOI:10.1021/ja031906i
日期:2004.3.1
during an enantioselectivereaction, this work represents the first example of this phenomenon outside of a protein. A chiral, nonracemic BisAMidine (BAM) ligand was designed, synthesized, and complexed to the proton of a Brønsted acid. The resulting coordination compound catalyzed the production of enantioenriched product from the combination of a Schiff base and nitroalkane (the aza-Henryreaction). This
Biodegradable Chitosan-Derived Thioureas as Recoverable Supported Organocatalysts - Application to the Stereoselective Aza-Henry Reaction
作者:José M. Andrés、Fernando González、Alicia Maestro、Rafael Pedrosa、María Valle
DOI:10.1002/ejoc.201700582
日期:2017.7.7
polymers. These organocatalysts are able to promote the enantioselective aza-Henry reaction with good yields and enantioselection. The activity and stereoselectivity of those materials are dependent on the accessibility of the reactants to the active site, and they increase with the length of the tether connecting the thiourea and the biopolymer. The best catalyst can be recovered and recycled for