Development of a Strategy for Linear-Selective Cu-Catalyzed Reductive Coupling of Ketones and Allenes for the Synthesis of Chiral γ-Hydroxyaldehyde Equivalents
作者:Raphael K. Klake、Samantha L. Gargaro、Skyler L. Gentry、Sharon O. Elele、Joshua D. Sieber
DOI:10.1021/acs.orglett.9b02973
日期:2019.10.4
N-substituted allyl equivalents generated from a chiral allenamide. By choice of the appropriate ligand for the Cu-catalyst, high linear selectivity can be obtained with good diastereocontrol. This methodology allows access to chiral γ-hydroxyaldehyde equivalents that were applied in the synthesis of chiral γ-lactones and 2,5-disubstitued tetrahydrofurans.
Pseudo-macrocyclic chelation control in remote asymmetric induction. Highly efficient 1,7-asymmetric inductive hydride reduction and Grignard reaction of γ-keto esters of 1,1′-binaphthalen-2-ols bearing an appropriate oligoether group as the 2′-substituent
Highly efficient 1,7-asymmetricinduction was achieved in DIBAL-H reduction and Grignard reaction of γ-keto esters of podand-type 1,1′-binaphthalen-2-ol derivatives bearing an appropriate oligoether group as the 2′-substituent. Thus, the DIBAL-H reduction of keto esters 4 in dichloromethane–toluene at –78 °C in the presence of an excess of MgBr2·OEt2 afforded, after further reduction of the resulting
Chiral ligand control in enantioselective reduction of ketones by SmI2 for ketyl radical addition to olefins
作者:Koichi Mikami、Makoto Yamaoka
DOI:10.1016/s0040-4039(98)00799-0
日期:1998.6
Samarium(II) diiodide-mediated reductive coupling of ketones with α,β-unsaturated esters is shown to afford enantioselectively γ-butyrolactones by the addition of 2,2′-bis(diphenylphosphinyl)-1,1′-binaphthyl (BINAPO) as a chiral ligand.
Application of an ephedrine chiral linker in a solid-phase, ‘asymmetric catch-release’ approach to γ-butyrolactones
作者:Nessan J. Kerrigan、Panee C. Hutchison、Tom D. Heightman、David J. Procter
DOI:10.1039/b302471g
日期:——
A Sm(II)-mediated, asymmetric, intermolecular ketyl-olefin addition employing α,β-unsaturated esters linked to resin through an ephedrine âchiral linkâ has been applied in a direct âasymmetric catch-releaseâ approach to γ-butyrolactones.
Enantioselective Synthesis of γ-Aryl-γ-butyrolactones by Sequential Asymmetric Epoxidation, Ring Expansion, and Baeyer−Villiger Oxidation
作者:Bin Wang、Yu-Mei Shen、Yian Shi
DOI:10.1021/jo061341j
日期:2006.12.1
N-tolyl-substituted oxazolidinone-containing ketone as catalyst and Oxone as oxidant via a sequential asymmetric epoxidation of benzylidenecyclopropanes, ring expansion, and Baeyer−Villigeroxidation. Up to 91% ee was obtained. Optically active cyclobutanones can also be obtained by suppressing the Baeyer−Villigeroxidation with use of more ketone catalyst and less Oxone.