Reagent-controlled enantioselectivity switch for the asymmetric fluorination of β-ketocarbonyls by chiral primary amine catalysis
作者:Yang'en You、Long Zhang、Sanzhong Luo
DOI:10.1039/c6sc03109a
日期:——
enantioselectivity switch was uncovered in the asymmetric α-fluorination of β-ketocarbonyls by a chiral primary amine catalyst. By a simple swap of fluorination reagents, both enantiomers of the quaternary fluorination adducts could be obtained with good yields and high enantioselectivity. Mechanistic studies disclosed dual H-bonding and electrostatic stereocontrolling modes for the catalysis.
Chiral Primary Amine/Ketone Cooperative Catalysis for Asymmetric α-Hydroxylation with Hydrogen Peroxide
作者:Mao Cai、Kaini Xu、Yuze Li、Zongxiu Nie、Long Zhang、Sanzhong Luo
DOI:10.1021/jacs.0c11787
日期:2021.1.20
catalytic strategies, aminocatalysis and carbonyl catalysis do not coexist well, and, as such, a cooperative amine/carbonyl dual catalysis remains essentially unknown. Here we report a cooperative primary amine and ketone dual catalytic approach for the asymmetric α-hydroxylation of β-ketocarbonyls with H2O2. Besides participating in the typical enamine catalytic cycle, the chiral primary amine catalyst
The selective and direct introduction of the fluorine atom into the α-position of β-dicarbonylcompounds was electrochemically achieved using iodotoluene difluoride as the mediator. The resulting α-fluoro-β-dicarbonyl compounds are important building blocks for biologically active compounds.
Asymmetric Enamine Catalysis with β-Ketoesters by Chiral Primary Amine: Divergent Stereocontrol Modes
作者:Changming Xu、Long Zhang、Sanzhong Luo
DOI:10.1021/jo502152w
日期:2014.12.5
aminocatalysis with α-substituted β-ketoesters. A simple chiral primary amine catalyst was identified to enable unprecedentedly effective catalysis of β-ketoesters in α-hydrazination and Robinson annulation reaction with good yields and high enantioselectivities. Stoichiometric experiments with preformed enamine ester intermediates revealed their enamine-catalytic nature as well as the critical roles of acidic
Chiral Primary Amine/Palladium Dual Catalysis for Asymmetric Allylic Alkylation of β-Ketocarbonyl Compounds with Allylic Alcohols
作者:Han Zhou、Long Zhang、Changming Xu、Sanzhong Luo
DOI:10.1002/anie.201505946
日期:2015.10.19
promote the direct asymmetric allylic alkylation (AAA) of β‐ketocarbonyl compounds. In particular, the synergistic dual catalytic system enabled the AAA reaction of challenging acyclic aliphatic ketones, such as β‐ketocarbonyl compounds and 1,3‐diketones.