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- Davor Šakić
- University of Zagreb Faculty of Pharmacy and Biochemistry Ante Kovačića 1 10000 Zagreb Croatia
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- Hendrik Zipse
- Department of Chemistry LMU Muenchen Butenandtstrasse 5–13 81377 Muenchen Germany
書誌事項
- 公開日
- 2016-09-21
- 権利情報
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- http://onlinelibrary.wiley.com/termsAndConditions#vor
- DOI
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- 10.1002/adsc.201600629
- 公開者
- Wiley
この論文をさがす
説明
<jats:title>Abstract</jats:title><jats:p>The stability of N‐centered radicals and radical cations of potential relevance in C–H amidation reactions has been quantified using highly accurate theoretical methods. Combination with available C–H bond energies for substrate fragments allows for the prediction of reaction enthalpies in 1,5‐hydrogen atom transfer (HAT) steps frequently encountered in reactions such as the Hofmann–Löffler–Freytag (HLF) reaction. Protonation of N‐radicals is found to be essential in classical HLF reactions for thermochemically feasible HAT steps. The stability of neutral N‐radicals depends strongly on the type of <jats:italic>N</jats:italic>‐substituent. Among the electron‐withdrawing substituents, the trifluoroacetyl (TFA) group is the least and the toluenesulfonyl (tosyl) group the most stabilizing. This implies that TFA‐aminyl radicals have the broadest and tosyl‐aminyl radicals the smallest window of synthetic applicability. In how far the intramolecular C–H amidation reactions compete with hydrogen abstraction from common organic solvents can be judged based on a comparison of reaction thermodynamics.</jats:p><jats:p><jats:boxed-text content-type="graphic" position="anchor"><jats:graphic xmlns:xlink="http://www.w3.org/1999/xlink" mimetype="image/png" position="anchor" specific-use="enlarged-web-image" xlink:href="graphic/adsc201600629-toc-0001-m.png"><jats:alt-text>magnified image</jats:alt-text></jats:graphic></jats:boxed-text> </jats:p>
収録刊行物
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- Advanced Synthesis & Catalysis
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Advanced Synthesis & Catalysis 358 (24), 3983-3991, 2016-09-21
Wiley
