Additive‐Free Isomerization of Allylic Alcohols to Ketones with a Cobalt PNP Pincer Catalyst
作者:Brian Spiegelberg、Andrea Dell'Acqua、Tian Xia、Anke Spannenberg、Sergey Tin、Sandra Hinze、Johannes G. de Vries
DOI:10.1002/chem.201901148
日期:2019.6.12
Catalyticisomerization of allylic alcohols in ethanol as a green solvent was achieved by using air and moisture stable cobalt (II) complexes in the absence of any additives. Under mild conditions, the cobalt PNP pincer complex substituted with phenyl groups on the phosphorus atoms appeared to be the most active. High rates were obtained at 120 °C, even though the addition of one equivalent of base
The catalytic activity of the ruthenium(II) complex [RuCp∗(CH3CN)3][PF6] 1 in the transposition of allylicalcohols into carbonyl compounds, in acetonitrile, is reported. This catalyst has proven to be able to catalyze the transformation of poorly reactive and/or functionalized substrates under smooth conditions.
Lithiated ambident anions derivedfrom (1-alkyl-2-propenyl)- or (1-phenyl-2-propenyl)-pentamethyl phosphoric triamides undergo regioselectively γ-reaction with various alkylating reagents and isobutyraldehyde. Further hydrolysis of adducts releases the ketone under acid conditions. Number of synthetic applications clearly show the ketone homoenolate behaviour of these new carbanions.
Manganese PNP-pincer catalyzed isomerization of allylic/homo-allylic alcohols to ketones – activity, selectivity, efficiency
作者:Tian Xia、Brian Spiegelberg、Zhihong Wei、Haijun Jiao、Sergey Tin、Sandra Hinze、Johannes G. de Vries
DOI:10.1039/c9cy01502g
日期:——
obtained using a solvent-free reaction system. A detailed DFT study reveals a self-dehydrogenation/hydrogenation reaction mechanism which was verified by the isolation of the α,β-unsaturated ketone as intermediate and a deuteriumlabeling experiment. It also provided a rationale for the observed selectivity and the higher efficiency of phenyl over isopropyl substitution.
Cp*Ru(PN) Complex-Catalyzed Isomerization of Allylic Alcohols and Its Application to the Asymmetric Synthesis of Muscone
作者:Masato Ito、Sachiko Kitahara、Takao Ikariya
DOI:10.1021/ja050770g
日期:2005.5.1
Highly efficient isomerization of allylicalcohols into saturated carbonyls is accomplished using the catalyst system of Cp*RuCl[Ph2P(CH2)2NH2-kappa2-P,N]-KOt-Bu (Cp* = eta5-C5(CH3)5) under mild conditions. Mechanistic consideration based on isotope-labeling experiments indicated the present reaction is applicable to the asymmetricisomerization of racemic sec-allylic alcohols with a prochiral olefin