Synthetic and Computational Study of Tin-Free Reductive Tandem Cyclizations of Neutral Aminyl Radicals
| Autor: | Hansamali S. Sirinimal, H. Bernhard Schlegel, Gregory J. Rosenhauer, Heng Chen, Ganesh Samala, Sebastien P. Hebert, Jennifer L. Stockdill |
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| Rok vydání: | 2018 |
| Předmět: |
Olefin fiber
Free Radicals Tandem 010405 organic chemistry Chemistry Radical Organic Chemistry Molecular Conformation chemistry.chemical_element 010402 general chemistry Photochemistry 01 natural sciences Biochemistry Article Catalysis 0104 chemical sciences Cyclization Yield (chemistry) Computer Simulation Reactivity (chemistry) Amines Physical and Theoretical Chemistry Chemoselectivity Tin |
| Zdroj: | Organic Letters. 20:6340-6344 |
| ISSN: | 1523-7052 1523-7060 |
| DOI: | 10.1021/acs.orglett.8b02456 |
| Popis: | 5- exo, 5- exo Cyclizations of conformationally unbiased propargylic aminyl radicals proceed with excellent yield, chemoselectivity, and diastereoselectivity under tin-free reductive cyclization conditions, regardless of the electronic environments and intermediate radical stabilization resulting from various olefin substituents. These conditions avoid the need for slow addition of initiator and reductant. By contrast, analogous 6- exo, 5- exo cyclizations require substituents capable of intermediate radical stabilization to avoid premature reduction products. These experimental results are corroborated by computations that further establish the reactivity of these aminyl radicals upon exposure to tin-free cyclization conditions. |
| Databáze: | OpenAIRE |
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