The Skeletal Rearrangement of Gold- and Platinum-Catalyzed Cycloisomerization of <i>cis</i>-4,6-Dien-1-yn-3-ols: Pinacol Rearrangement and Formation of Bicyclo[4.1.0]heptenone and Reorganized Styrene Derivatives
作者:Jhih-Meng Tang、Sabyasachi Bhunia、Shariar Md. Abu Sohel、Ming-Yuan Lin、Hsin-Yi Liao、Swarup Datta、Arindam Das、Rai-Shung Liu
DOI:10.1021/ja076175r
日期:2007.12.1
cyclized products chemoselectively. The AuCl3-catalyzed cyclizations of 6-substituted cis-4,6-dien-1-yn-3-ols proceeded via a 6-exo-dig pathway to give allyl cations, which subsequently undergo a pinacol rearrangement to produce reorganized cyclopentenyl aldehyde products. Using chiral alcohol substrates, such cyclizations proceed with reasonable chirality transfer. In the PtCl2-catalyzed cyclization of
We report herein a nickel-catalyzed ring-opening allylation of cyclopropanols with allylic carbonates that occurs under mild and neutral conditions. The reaction displays linear selectivity for both linear and branched acyclic allylic carbonates and is also applicable to cyclic allylic carbonates, affording a variety of δ,ε-unsaturated ketones in moderate to good yields. Mechanistic experiments are
A Convenient Synthesis of 2-Naphthylcyclopentanones and 2-Naphthylcyclohexanones from 1-Naphthylcycloalkenes
作者:Maciej Góra、Michał K. Łuczyński、Janusz J. Sepioł
DOI:10.1055/s-2005-865298
日期:——
The oxidation of naphthylcycloalkenes with hydrogen peroxide or MCPBA followed by acid catalyzed rearrangement of diol (epoxide), afforded a series of naphthylcycloalkanones in a very simple manner. The conditions allow preparation of naphthylcycloalkanones on a multigram scale.
A kineticresolution of racemic 2-substituted cyclopentanones via highly regio- and enantioselective Baeyer–Villiger oxidation has been successfully developed. The reaction could afford the normal 6-substituted δ-lactones in up to 98% ee and >19/1 regioselectivity. Meanwhile, the unreacted ketones were recovered in excellent ee values (up to 98%). It represents the best results of the kinetic resolution
Nickel-catalyzed Heck reaction of cycloalkenes using aryl sulfonates and pivalates
作者:Jianrong Steve Zhou、Xiaolei Huang、Shenghan Teng、Yonggui Robin Chi
DOI:10.1039/d1cc00634g
日期:——
Nickel-catalyzed Heck reaction of cycloalkenes delivers unusual conjugated arylated isomers. Nickel(0) catalysts ligated by chelating dialkylphosphines effectively activate not only aryl triflates as electrophiles, but also less reactive aryl mesylates, tosylates and pivalates. The omission of bases allows nickel hydride species to exist long enough to perform in situ olefin isomerization of initial