Iron Pincer Complexes as Catalysts and Intermediates in Alkyl–Aryl Kumada Coupling Reactions
作者:Gerald Bauer、Matthew D. Wodrich、Rosario Scopelliti、Xile Hu
DOI:10.1021/om501122p
日期:2015.1.12
bis(oxazolinylphenyl)amido pincer ligand (Bopa) to stabilize the catalytically active Fe center, resulting in isolation and characterization of well-defined ironcomplexes whose catalytic roles have been probed and confirmed. Reactivity studies of the ironcomplexes identify an Fe(II) “ate” complex, [Fe(Bopa-Ph)(Ph)2]−, as the active species for the oxidative addition of alkyl halide. Experiments using radical-probe
A NEW ONE-POT CROSS COUPLING REACTION OF THE GRIGNARD REAGENTS AND ALLYL ALCOHOLS VIA 2-ALLYLOXYPYRIDINIUM SALTS
作者:Teruaki Mukaiyama、Masanori Imaoka、Toshio Izawa
DOI:10.1246/cl.1977.1257
日期:1977.11.5
A new one-pot cross coupling reaction of the Grignardreagents and allyl alcohols via 2-allyloxypyridinium salt was investigated. 2-Allyloxy-1-ethyl-4,6-dimethylpyridinium salts, prepared in situ from allyl alcohols and 1-ethyl-2-fluoro-4,6-dimethylpyridinium tetrafluoroborate, reacted easily with the Grignardreagents to afford the corresponding cross coupling products in good yield.
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%)
The Cu‐free asymmetric allylic alkylation, catalysed by NHC, with Grignardreagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85 % ee) on large and various substrates, regardless of the nature of the Grignardreagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives
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)。