Iridium-Catalyzed Asymmetric Allylic Amination with Polar Amines: Access to Building Blocks with Lead-Like Molecular Properties
作者:Paolo Tosatti、Joachim Horn、Amanda J. Campbell、David House、Adam Nelson、Stephen P. Marsden
DOI:10.1002/adsc.201000721
日期:2010.12.17
dimethyl sulfoxide (DMSO) allowed, for the first time, the systematic exploitation of highly polar, functionalized amines in asymmetricallylic substitutions: low molecular weight, sp3-rich chiral buildingblocks were obtained with physicochemical properties that will be valuable in the synthesis of lead-like small molecules.
Catalytic Dynamic Kinetic Resolutions with N-Heterocyclic Carbenes: Asymmetric Synthesis of Highly Substituted β-Lactones
作者:Daniel T. Cohen、Chad C. Eichman、Eric M. Phillips、Emily R. Zarefsky、Karl A. Scheidt
DOI:10.1002/anie.201203382
日期:2012.7.16
New DKR type: An N‐heterocyclic carbene (NHC)‐catalyzed dynamic kinetic resolution of racemic α‐substituted β‐keto esters has been developed. This method relies on the epimerization of an NHC‐enol intermediate before subsequent aldol/acylation events. Highly substituted β‐lactones are produced in good yield with good to excellent selectivities (see scheme).
Substrate-Regiocontrolled Synthesis of Enantioenriched Allylic Amines by Palladium-Catalysed Asymmetric Allylic Amination: Formal Synthesis of Fagomine
or the protected derivative, respectively. Unhindered primary amines can be used as nucleophiles, thus enlarging the scope of the Pd/DACH catalytic system. Hydrogen bonding involving the free hydroxy group in the unprotected allylic carbonate is proposed to be responsible for the control of the regioselectivity to afford branched isomers, obtained in high ee. A short and enantioselective formal synthesis
Acyclic nucleoside phosphonates have been prepared in a straightforward manner and in high yields by an enantioselectivepalladium-catalyzedallylicsubstitution involving nucleic bases as nucleophiles followed by cross-metathesis reaction with diethyl allylphosphonate.
Palladium(0)-catalyzed asymmetric synthesis of 2-vinylmorpholine and 2-vinylpiperazine. Influence of the biscarbonate structure on the enantioselectivity
作者:Magali Massacret、Rajae Lakhmiri、Paul Lhoste、Christelle Nguefack、Fouad B Ben Abdelouahab、Rachid Fadel、Denis Sinou
DOI:10.1016/s0957-4166(00)00315-3
日期:2000.9
Palladium-catalyzed cyclization of N,N-bis(p-tolylsulfonyl)-o-phenylenediamine 2b and 2-[(2,4,6-trimethylphenyl)sulfonyl] aminophenol 2c with three allylic biscarbonates 1a-c gave quite different enantioselectivities. This indicates that the cyclization processes do not have a common intermediate, as in the case of benzene-1,2-diol. (C) 2000 Elsevier Science Ltd. All rights reserved.