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
When benzylic and allylic alcohols were treated with enolacetate in the presence of a catalytic amount of a rhenium complex, ReBr(CO)5, the carbon-carbon bond formation of the alcohols and enolacetate smoothly proceeded to give the corresponding ketones and aldehyde in moderate to good yields. For the reaction of allylic alcohols, γ,δ-unsaturated carbonylcompounds were obtained in good yields. When