Tuning of Regioselectivity in the Coupling Reaction Involving Allenic/Propargylic Palladium Species
作者:Shengming Ma、Aibin Zhang
DOI:10.1021/jo0111098
日期:2002.4.1
Two different types of coupling patterns for the Pd(0)-catalyzed coupling reaction of allenic/propargylic zinc reagents with organic halides or propargylic carbonates (acetate) with the corresponding organometallicreagents were observed. After studying the controlling factors on the regioselectivity of this reaction, we demonstrated that the steric hindrance of both reactants and the types of organic
Studies of iron-mediated Pauson–Khand reactions of 1,1-disubstituted-allenylsilanes: mechanistic implications for a reactive three-membered iron metallacycle
作者:David R. Williams、Akshay A. Shah、Shivnath Mazumder、Mu-Hyun Baik
DOI:10.1039/c2sc21404k
日期:——
Pauson–Khandreactions of 1,1-disubstituted allenylsilanes have been explored using diiron nonacarbonyl. These studies describe the characterization of three-membered iron metallacycles as reaction-competent intermediates leading to stereoselective formation of highly functionalized 4-alkylidene-2-cyclopenten-1-ones. Studies of the reaction profile provide insights leading to the proposal of a stereoselective