Visible photocatalysis of novel oxime phosphonates: synthesis of β-aminophosphonates
作者:Yong-Hong Li、Chun-Hai Wang、Su-Qian Gao、Feng-Ming Qi、Shang-Dong Yang
DOI:10.1039/c9cc06075h
日期:——
A novel type of oxime phosphonate was synthesized and used in the intermolecular cascade radical addition reaction of alkenes to access β-aminophosphonates via visible-light-driven N-centered iminyl radical-mediated and redox-neutral selective C–P single-bond cleavage in an active phosphorus radical route. The procedure is characterized by its ability to achieve the construction of Csp3–P and Csp3–N
Bidentate Hydroxyalkyl NHC Ligands for the Copper-Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Grignard Reagents
作者:Magaly Magrez、Yann Le Guen、Olivier Baslé、Christophe Crévisy、Marc Mauduit
DOI:10.1002/chem.201203969
日期:2013.1.21
Demonstrating their potential: Bidentate alkoxy NHC ligands have been used in the copper‐catalyzed asymmetricallylic alkylation of allylphosphates with Grignard reagents (see scheme). The method provides access to tertiary and quaternary chiral centers with high regio‐ and enantioselectivity. The system is also applied to the synthesis of chiral E,E‐dienes, a key structural motif prevalent in natural
Improvements and Applications of the Transition Metal-Free Asymmetric Allylic Alkylation using Grignard Reagents and Magnesium Alanates
作者:David Grassi、Alexandre Alexakis
DOI:10.1002/adsc.201500495
日期:2015.10.12
Two new N-heterocyclic carbene (NHC) ligands have been synthesized and employed in the transition metal-free asymmetric allylic alkylation (AAA) mediated by Grignardreagents and magnesium alanates. The employment of these ligands showed high yields and improved regio- and enantioselectivity in the formation of tertiary and quaternary stereocenters. Moreover, the low catalyst loading (up to 0.3 mol%)
Copper-Free Asymmetric Allylic Alkylation with Grignard Reagents
作者:Olivier Jackowski、Alexandre Alexakis
DOI:10.1002/anie.201000577
日期:2010.4.26
Open wide and say AAA: The copper‐free asymmetric allylicalkylation reaction of Grignardreagents, catalyzed by N‐heterocyclic carbenes, is reported for allyl bromide derivatives. This reaction offers good enantioselectivity and good to excellent γ regioselectivity, particularly for the formation of quaternary chiral centers (see scheme; Mes=mesityl).
张开嘴说AAA:据报道,N-杂环卡宾催化了格氏试剂的无铜不对称烯丙基烷基化反应,是烯丙基溴衍生物的反应。该反应提供了良好的对映选择性和良好的至优异的γ区域选择性,特别是对于形成四元手性中心(参见方案; Mes =甲磺酰基)。
Synthesis of Optically Active β- or γ-Alkyl-Substituted Alcohols through Copper-Catalyzed Asymmetric Allylic Alkylation with Organolithium Reagents
作者:Sureshbabu Guduguntla、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1021/jo401536u
日期:2013.9.6
An efficient one-pot synthesis of optically active β-alkyl-substituted alcohols through a tandem copper-catalyzedasymmetricallylicalkylation (AAA) with organolithium reagents and reductive ozonolysis is presented. Furthermore, hydroboration–oxidation following the Cu-catalyzed AAA leads to the corresponding homochiral γ-alkyl-substituted alcohols.