Computational Study of Bridge Splitting, Aryl Halide Oxidative Addition to Pt II , and Reductive Elimination from Pt IV : Route to Pincer‐Pt II Reagents with Chemical and Biological Applications
| Autor: | Alireza Ariafard, Allan J. Canty, Gerard van Koten |
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| Rok vydání: | 2021 |
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| Zdroj: | Chemistry – A European Journal. 27:15426-15433 |
| ISSN: | 1521-3765 0947-6539 |
| DOI: | 10.1002/chem.202102687 |
| Popis: | Density functional theory computation indicates that bridge splitting of [PtII R2 (μ-SEt2 )]2 proceeds by partial dissociation to form R2 Pta (μ-SEt2 )Ptb R2 (SEt2 ), followed by coordination of N-donor bromoarenes (L-Br) at Pta leading to release of Ptb R2 (SEt2 ), which reacts with a second molecule of L-Br, providing two molecules of PtR2 (SEt2 )(L-Br-N). For R=4-tolyl (Tol), L-Br=2,6-(pzCH2 )2 C6 H3 Br (pz=pyrazol-1-yl) and 2,6-(Me2 NCH2 )2 C6 H3 Br, subsequent oxidative addition assisted by intramolecular N-donor coordination via PtII Tol2 (L-N,Br) and reductive elimination from PtIV intermediates gives mer-PtII (L-N,C,N)Br and Tol2 . The strong σ-donor influence of Tol groups results in subtle differences in oxidative addition mechanisms when compared with related aryl halide oxidative addition to palladium(II) centres. For R=Me and L-Br=2,6-(pzCH2 )2 C6 H3 Br, a stable PtIV product, fac-PtIV Me2 {2,6-(pzCH2 )2 C6 H3 -N,C,N)Br is predicted, as reported experimentally, acting as a model for undetected and unstable PtIV Tol2 {L-N,C,N}Br undergoing facile Tol2 reductive elimination. The mechanisms reported herein enable the synthesis of PtII pincer reagents with applications in materials and bio-organometallic chemistry. |
| Databáze: | OpenAIRE |
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