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

Abstract

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 ether was also considered. Both C6H5OC≡CSiiPr3 and C6H5OC≡CSiMe3 were chosen as the substrates. The reactions involve C−H activation of substrate, acetic acid rotation, H transformation, MeC≡CMe or substrate insertion into Pd-phenyl bond and reductive elimination steps. It is found that the cycloaddition is favored for C6H5OC≡CSiiPr3, while dimerization is preferred for C6H5OC≡CSiMe3, because the steric repulsion between two bulky SiiPr3 groups is relatively larger and steric repulsion between two little SiMe3 groups is relatively small. In addition, besides C6H5OC≡CSiiPr3, other four substrates C6H5CH2C≡CSiiPr3, C6H5C(O)C≡CSiiPr3, C6H5SC≡CSiiPr3 and C6H5N(H)C≡CSiiPr3 have been calculated as the substrates for cycloaddition reaction with MeC≡CMe. Among the five substrates, C6H5OC≡CSiiPr3 has the lowest energy barrier (29.9 kcal/mol), consistent with the experimental observation that C6H5OC≡CSiiPr3 is the appropriate substrate for successful cycloaddition.

Back to tab navigation

Supplementary files

Article information


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

Dalton Trans., 2020, Accepted Manuscript
Article type
Paper

DFT Study on the Mechanism of Bimetallic Pd−Zn-Catalyzed Cycloaddition of Alkynyl Aryl Ethers with Internal Alkynes

J. Liu, M. WANG, L. Chen and B. Li, Dalton Trans., 2020, Accepted Manuscript , DOI: 10.1039/C9DT04362D

Social activity

Search articles by author

Spotlight

Advertisements