mild amine basic conditions is described. A cooperative catalysis of CpRu complex, DBU, and NaPF6 enables chemoselective and catalytic generation of nucleophiles from barely acidic acetonitrile, which is integrated into the addition to aldehydes, imines, and activated ketones. Mechanistic investigations revealed that the three catalyst components work together to achieve high catalytic efficiency.
Photoredox-catalyzed deoxyfluorination of activated alcohols with Selectfluor®
作者:María González-Esguevillas、Javier Miró、Jenna L. Jeffrey、David W.C. MacMillan
DOI:10.1016/j.tet.2019.05.043
日期:2019.8
Herein we disclose a deoxyfluorination of alcohols with an electrophilic fluorine source via visible-light photoredox catalysis. This radical-mediated C–F coupling is capable of fluorinating secondary and tertiary alcohols efficiently, complementing previously reported nucleophilic deoxyfluorination protocols.
Biocatalytic Cascade for the Synthesis of Enantiopure β-Azidoalcohols and β-Hydroxynitriles
作者:Joerg H. Schrittwieser、Iván Lavandera、Birgit Seisser、Barbara Mautner、Wolfgang Kroutil
DOI:10.1002/ejoc.200900091
日期:2009.5
one-pot reaction sequence starting from prochiral α-chloroketones leading to enantiopure β-azidoalcohols and β-hydroxynitriles is described. Asymmetric bioreduction of α-chloroketones by hydrogen transfer catalysed by an alcohol dehydrogenase (ADH) established the stereogenic centre in the first step to furnish enantiopure chlorohydrin intermediates. Subsequent biocatalysed ring closure to the epoxide
Alpha,beta-unsaturated nitriles are readily synthesized by eliminating MgO from beta-hydroxynitriles. Deprotonating acyclic, and cyclic, beta-hydroxynitriles with excess MeMgCl smoothly generates dianion intermediates that eject MgO with concurrent formation of alpha,beta-unsaturated nitriles. Alternatively, sequential addition of lithioacetonitrile and MgBr(2) to aldehydes and ketones generates magnesium
Ring Opening of Epoxides with Acetone Cyanohydrin Catalyzed by Lanthanoid(III) Alkoxides
作者:Hiroshi Ohno、Atsunori Mori、Shohei Inoue
DOI:10.1246/cl.1993.975
日期:1993.6
Ring opening of epoxide and aziridine with acetonecyanohydrin is promoted by a catalytic amount of lanthanoid(III) alkoxide to provide β-hydroxy nitrile and β-amino nitrile, respectively.