Formation of Quaternary Stereogenic Centers by Copper-Catalyzed Asymmetric Conjugate Addition Reactions of Alkenylaluminums to Trisubstituted Enones
作者:Daniel Müller、Alexandre Alexakis
DOI:10.1002/chem.201302856
日期:2013.11.4
undergo asymmetric copper‐catalyzedconjugateaddition (ACA) to β‐substituted enones allowing the formation of stereogenic all‐carbon quaternary centers. Phosphinamine–copper complexes proved to be particularly active and selective compared with phosphoramidite ligands. After extensive optimization, high enantioselectivities (up to 96 % ee) were obtained for the addition of alkenylalanes to β‐substituted
α-Selective Ni-Catalyzed Hydroalumination of Aryl- and Alkyl-Substituted Terminal Alkynes: Practical Syntheses of Internal Vinyl Aluminums, Halides, or Boronates
作者:Fang Gao、Amir H. Hoveyda
DOI:10.1021/ja104896b
日期:2010.8.18
A method for Ni-catalyzed hydroalumination of terminalalkynes, leading to the formation of alpha-vinylaluminum isomers efficiently (>98% conv in 2-12 h) and with high selectivity (95% to >98% alpha), is described. Catalytic alpha-selective hydroalumination reactions proceed in the presence of a reagent (diisobutylaluminum hydride; dibal-H) and 3.0 mol % metal complex (Ni(dppp)Cl(2)) that are commercially
A Multicomponent Ni-, Zr-, and Cu-Catalyzed Strategy for Enantioselective Synthesis of Alkenyl-Substituted Quaternary Carbons
作者:Kevin P. McGrath、Amir H. Hoveyda
DOI:10.1002/anie.201309456
日期:2014.2.10
of alkenyl groups to acyclic trisubstituted enones, an advance achieved by adopting an easily modifiable and fully catalytic approach. The requisite alkenylaluminum reagents are synthesized with exceptional site‐ and/or stereoselectivity by a Ni‐catalyzed hydroalumination process, and the necessary enones are prepared through a site‐ and stereoselective zirconocene‐catalyzed carboalumination/acylation
Tandem Hydroalumination/Cu-Catalyzed Asymmetric Vinyl Metalation as a New Access to Enantioenriched Vinylcyclopropane Derivatives
作者:Daniel S. Müller、Veronika Werner、Sema Akyol、Hans-Günther Schmalz、Ilan Marek
DOI:10.1021/acs.orglett.7b01661
日期:2017.8.4
Herein, we report the first enantio- and diastereoselective addition of stereodefined vinyl organometallicreagents to cyclopropenes. The operationally simple tandem hydroalumination and copper-catalyzed vinylmetalation allows for the unique access of a diverse set of enantioenriched vinylcyclopropane derivatives.
An umpolung strategy has been developed for the synthesis of β,γ-unsaturatedketones utilizing nucleophilic β-alkenylation of N-alkoxyenamines, which are prepared in situ fromketones and isoxazolidine, with alkenyl aluminum reagents. Various β,γ-unsaturatedketones have been prepared following this simple procedure under mild conditions.