Remarkably simple IrIII catalysts enable the isomerization of primary and sec‐allylicalcohols under very mild reaction conditions. X‐ray absorption spectroscopy (XAS) and mass spectrometry (MS) studies indicate that the catalysts, with the general formula [Cp*IrIII], require a halide ligand for catalytic activity, but no additives or additional ligands are needed.
非常简单的Ir III催化剂可在非常温和的反应条件下实现伯醇和仲烯丙基醇的异构化。X射线吸收光谱(XAS)和质谱(MS)研究表明,通式为[Cp * Ir III ]的催化剂需要卤化物配体才能发挥催化活性,但不需要添加剂或其他配体。
Ir-catalysed formation of C−F bonds. From allylic alcohols to α-fluoroketones
作者:Nanna Ahlsten、Belén Martín-Matute
DOI:10.1039/c1cc12653a
日期:——
A novel iridium-catalysed tandem isomerisation/CâF bond formation from allylic alcohols and Selectfluor® to prepare α-fluorinated ketones as single constitutional isomers is reported.
isomerized into enolates (enols) by [Cp*IrCl2]2. The enolates react with Selectfluor present in the reaction media. This method produces α-fluoroketones as single constitutional isomers in high yields. iridium - fluorine - isomerization - alcohols - fluoro ketones
yields and with excellent selectivities. Starting from allylic alcohols as the carbonyl precursors, the combination of a 1,3‐hydrogen shift catalyzed by iridium(III) with an electrophilic bromination gives α‐bromoketones and aldehydes in good to excellent yields. The selectivity of the process is determined by the structure of the starting allylic alcohol; thus, α‐bromoketones formally derived from unsymmetrical
CX (X=Br, I) Bond-Tolerant Aerobic Oxidative Cross- Coupling: A Strategy to Selectively Construct β-Aryl Ketones and Aldehydes
作者:Mao Chen、Jie Wang、Ziyi Chai、Cai You、Aiwen Lei
DOI:10.1002/adsc.201100782
日期:2012.2
aryl halide-containing β-aryl ketones and aldehydes can be synthesized directly from readily available allyic alcohols and boronic acids via palladium-catalyzedoxidativecross-coupling reactions. The dual roles of copper, including electron-carrier and Lewis acid functions, are supposed to be critical for the high reactivity and selectivity of this aerobic oxidative coupling transformation.