Nickel acetylacetonate is an efficient catalyst for the 1,4-addition of trimethylaluminum to α,β-unsaturated ketones. The reaction is strongly solvent dependent and gives best results in tetrahydrofuran or ethyl acetate. The reaction is especially useful for the nucleophilic 1,4-methyl transfer to sterically hindered enones. A β-cuparenone synthesis via conjugate methyl group addition to an enone precursor is described.
Radical Cyclization of Alkene-Tethered Ketones Initiated by Hydrogen-Atom Transfer
作者:Mar Saladrigas、Caroline Bosch、Gisela V. Saborit、Josep Bonjoch、Ben Bradshaw
DOI:10.1002/anie.201709659
日期:2018.1.2
An unprecedented C−C coupling reaction between alkenes and ketones by hydrogen‐atom transfer, using Fe(acac)3 and PhSiH3 in EtOH, is described. This mild protocol features high site selectivity and allows the construction of sterically congested structures containing tertiary alcohols and quaternary centers. The overall process introduces a novel strategic bond disconnection for ring‐closing reactions