Jump to main content
Jump to site search


DFT study on the mechanism of bimetallic Pd–Zn-catalyzed cycloaddition of alkynyl aryl ethers with internal alkynes

Author affiliations

Abstract

The reaction mechanism of bimetallic Pd–Zn-catalyzed cycloaddition of alkynyl aryl ethers with internal alkynes has been studied theoretically. Besides cycloaddition reaction, the dimerization of alkynyl aryl ethers was also considered. Both C6H5OC[triple bond, length as m-dash]CSiiPr3 and C6H5OC[triple bond, length as m-dash]CSiMe3 were chosen as the substrates. The reactions involve C–H activation of the substrate, acetic acid rotation, H transformation, MeC[triple bond, length as m-dash]CMe or substrate insertion into the Pd–phenyl bond and reductive elimination steps. It is found that cycloaddition is favored for C6H5OC[triple bond, length as m-dash]CSiiPr3, while dimerization is preferred for C6H5OC[triple bond, length as m-dash]CSiMe3, because the steric repulsion between two bulky SiiPr3 groups is relatively large and the steric repulsion between two small SiMe3 groups is relatively small. In addition, besides C6H5OC[triple bond, length as m-dash]CSiiPr3, four other substrates C6H5CH2C[triple bond, length as m-dash]CSiiPr3, C6H5C(O)C[triple bond, length as m-dash]CSiiPr3, C6H5SC[triple bond, length as m-dash]CSiiPr3 and C6H5N(H)C[triple bond, length as m-dash]CSiiPr3 have been calculated as the substrates for cycloaddition reaction with MeC[triple bond, length as m-dash]CMe. Among the five substrates, C6H5OC[triple bond, length as m-dash]CSiiPr3 has the lowest energy barrier (29.9 kcal mol−1), consistent with the experimental observation that C6H5OC[triple bond, length as m-dash]CSiiPr3 is the appropriate substrate for successful cycloaddition.

Graphical abstract: DFT study on the mechanism of bimetallic Pd–Zn-catalyzed cycloaddition of alkynyl aryl ethers with internal alkynes

Back to tab navigation

Supplementary files

Article information


Submitted
11 Nov 2019
Accepted
25 Jan 2020
First published
30 Jan 2020

Dalton Trans., 2020, Advance Article
Article type
Paper

DFT study on the mechanism of bimetallic Pd–Zn-catalyzed cycloaddition of alkynyl aryl ethers with internal alkynes

M. Wang, L. Chen, B. Li and J. Liu, Dalton Trans., 2020, Advance Article , DOI: 10.1039/C9DT04362D

Social activity

Search articles by author

Spotlight

Advertisements