A general Pd-catalyzed α- and γ-benzylation of aldehydes for the formation of quaternary centers
作者:Ivan Franzoni、Laure Guénée、Clément Mazet
DOI:10.1039/c5ob00702j
日期:——
A palladium-catalyzed benzylation of α-branched aldehydes has been developed using benzyl methyl carbonates. The method gives access to congested quaternary centers in the vicinity of one of the most sensitive carbonyl functionalities and displays unprecedented generality with respect to both coupling partners. Evidence for the direct involvement of a Pd-η3-benzyl intermediate is provided. Extension
Stereoselective alkylation of the vinylketene silyl N,O-acetal possessing a chiral auxiliary has been achieved by using activated alkyl halides including allyl iodides, benzyl iodides, and propargyl iodide with Ag(I) ion in the presence of BF3·OEt2. The reaction proceeded to give reduced polyketides in high stereoselectivity. The synthesis of mycocerosic acid, a component of the cell envelope of Mycobacterium
Synthesis of benzylpalladium complexes through C–O bond cleavage of benzylic carboxylates: Development of a novel palladium-catalyzed benzylation of olefins
作者:Hirohisa Narahashi、Isao Shimizu、Akio Yamamoto
DOI:10.1016/j.jorganchem.2007.10.051
日期:2008.1
tertiary phosphines to give benzylpalladium(II) carboxylate complexes with cleavage of the benzyl-oxygen bond. The benzylpalladium complexes having the trifluoroacetato ligand react with olefins such as ethyl acrylate to give olefin benzylation products. On the basis of these studies a novel palladium-catalyzed benzylation of olefins was developed without using organic halides as the starting materials
Heck-type Benzylation of Olefins with Benzyl Trifluoroacetates
作者:Hirohisa Narahashi、Akio Yamamoto、Isao Shimizu
DOI:10.1246/cl.2004.348
日期:2004.3
A new synthetic method for 1-aryl-2-alkenes from 1-olefins by benzylation treating with benzyl trifluoroacetates using palladium-catalyst is developed on the basis of oxidative addition of benzyl carboxylates to Pd(0) complexes to give benzyl(carboxylato)palladium(II) complexes with cleavage of benzyl–oxygen bond.
Palladium-Catalyzed, Asymmetric Mizoroki–Heck Reaction of Benzylic Electrophiles Using Phosphoramidites as Chiral Ligands
作者:Zhigang Yang、Jianrong (Steve) Zhou
DOI:10.1021/ja304099j
日期:2012.7.25
We report herein the first examples of asymmetric Mizoroki-Heck reactions using benzyl electrophiles. A new phosphoramidite was identified to be an effective chiral ligand in the palladium-catalyzed reaction. The reaction is compatible with polar functional groups and can be readily scaled up. Several cyclic olefins worked well as olefin components. Thirty-one examples are included.