کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5216262 | 1383257 | 2014 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: On the mechanism of Pd(0)-catalyzed coupling of propargylic carbonates with N-tosylhydrazones: density functional theory survey On the mechanism of Pd(0)-catalyzed coupling of propargylic carbonates with N-tosylhydrazones: density functional theory survey](/preview/png/5216262.png)
In this article, we have theoretically investigated the possible reaction mechanisms for Pd(0)-catalyzed coupling of propargylic carbonates with N-tosylhydrazones. The Ïb97X-D method and C-PCM solvent model are used to describe the reaction processes. After the formation of allenylpalladium through C-O bond cleavage from propargylic carbonates, both decarboxylation and ligand exchange processes are explored. Then, depending on different conditions, we considered three possible types of reaction mechanisms, carbene insertion triggered by N2 release, C-C coupling reactions without N2 release, and C-C coupling reactions via the out-sphere attack of diazo compound. Our results indicate that it is favorable to undergo the carbene insertion into allenylpalladium after ligand exchange with diazo compound, which is partially agreement with the experimental suggestions. Although the decarboxylation is more difficult than ligand exchange, the reaction rate could be limited by Pd-catalyzed N2 dissociation from diazo compound. Additionally, it should be essential to select DFT-D method to describe this reaction.
Journal: Tetrahedron - Volume 70, Issue 49, 9 December 2014, Pages 9373-9380