Palladium-Catalyzed Cyclization of 1,ω-Dienols: Multiple Ways to Intramolecularly Trap a Carbocation
作者:Vasily N. Korotchenko、Michel R. Gagné
DOI:10.1021/jo0705871
日期:2007.6.1
The tandem catalytic cyclization-rearrangement of 1,omega-dien-3-ols by palladium(II) produces different types of products, depending on the structure of starting material. The pinacol rearrangement, benzannulation, and oxy-Cope rearrangement are major pathways of transforming the putative sigma-alkylpalladium carbocation. Turnover of the cyclization is achieved by beta-hydride elimination and reoxidation of palladium with benzoquinone. The overall course of the reaction is very sensitive to small changes in the substrate structure.
作者:Marvin Parasram、Viktor O. Iaroshenko、Vladimir Gevorgyan
DOI:10.1021/ja5104525
日期:2014.12.31
A palladium (Pd)-catalyzed endo-selectiveHeckreaction of iodomethylsilyl ethers of phenols and aliphatic alkenols has been developed. Mechanistic studies reveal that this silyl methyl Heckreaction operates via a hybrid Pd-radical process and that the silicon atom is crucial for the observed endo selectivity. The obtained allylic silyloxycycles were further oxidized into (Z)-alkenyldiols.