Copper-Catalyzed Asymmetric 1,4-Addition of Alkenyl Alanes to N-Substituted-2-3-dehydro-4-piperidones
摘要:
Readily available vinyl alanes are used in the Cu-catalyzed asymmetric conjugate addition reaction to N-substituted-2-3-dehydro-4-piperidones. The enhanced reactivity of recently developed and easily prepared phosphine amine ligands in combination with inexpensive Cu(II)naphtenate (CuNp) allows the introduction of a great variety of alkenyl, alkyl, and aryl aluminums in high enantioselectivity.
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
Nickel- or palladium-catalyzed cross coupling. 31. Palladium- or nickel-catalyzed reactions of alkenylmetals with unsaturated organic halides as a selective route to arylated alkenes and conjugated dienes: scope, limitations, and mechanism
作者:Eiichi Negishi、Tamotsu Takahashi、Shigeru Baba、David E. Van Horn、Nobuhisa Okukado
DOI:10.1021/ja00242a024
日期:1987.4
Al, Zr, and Zn were 2, 3, and > 2000 mmol of (E)-1-octenylbenzene (8) per mmol of Pd(PPh/sub3/)/sub 4/ per hour at room temperature, respectively. The stoichiometric reaction of PhPd(PPh/sub3/)/sub 2/I (6) with 1.2 equiv of (E)-1-octenylzinc chloride (7) in a 2:1 mixture of CD/sub 2/Cl/sub2/ and THF was examined in detail. The reaction follows second-order kinetics (k/sub2/ = 2.9 L/(mol.min) at
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.
Synthesis of Linear α,β-Unsaturated Amides from Isocyanates and Alkenylaluminum Reagents
作者:Xiao-Feng Wu、Bo Chen
DOI:10.1055/s-0037-1610753
日期:2020.5
A new approach has been developed for the synthesis of linear α,β-unsaturated amides by the direct coupling of isocyanates with alkenylaluminum reagents. At room temperature, the desired α,β-unsaturated amides were isolated in good to excellent yields with good functional-group tolerance in the absence of any catalyst or additive.