Copper-Catalyzed Radical 1,4-Difunctionalization of 1,3-Enynes with Alkyl Diacyl Peroxides and N-Fluorobenzenesulfonimide
| Autor: | Yihang Jiao, Liang Ge, Weili Deng, Xinhao Zhang, Changqing Ye, Xiaotao Zhu, Hongli Bao, Wujun Jian, Yuehua Zeng, Mong-Feng Chiou, Yajun Li |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Radical Regioselectivity General Chemistry 010402 general chemistry 01 natural sciences Biochemistry Combinatorial chemistry Catalysis Scavenger (chemistry) 0104 chemical sciences Colloid and Surface Chemistry N-fluorobenzenesulfonimide chemistry Reagent Radical clock Copper catalyzed Alkyl |
| Zdroj: | Journal of the American Chemical Society. 141:548-559 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.8b11499 |
| Popis: | Many reactions involving allenyl ion species have been studied, but reactions involving allenyl radicals are less well understood, perhaps because of the inconvenience associated with the generation of short-lived allenyl radicals. We describe here a versatile method for the generation of allenyl radicals and their previously unreported applications in the intermolecular 1,4-carbocyanation and 1,4-sulfimidocyanation of 1,3-enynes. With the assistance of the trifunctional reagents, alkyl diacyl peroxides or N-fluorobenzenesulfonimide, a range of synthetically challenging multisubstituted allenes can be prepared with high regioselectivity. These multisubstituted allenes can be easily transformed into synthetically useful structures such as fluorinated vinyl cyanides, lactones, functionalized allenyl amides, 1-aminonaphthalenes, and pyridin-2(1 H)-ones, and several novel transformations are reported. The results of radical scavenger and radical clock experiments are consistent with the proposed allenyl radical pathway. Density functional theory (DFT) and IR spectroscopy studies suggest the formation of an isocyanocopper(II) species in the ligand exchange step. On the basis of the results of IR, DFT, and diastereoselectivity studies, an isocyanocopper(II)/copper(I) catalytic cycle is proposed, which differs from the previously considered Cu(III) mechanism in cyanation reactions. |
| Databáze: | OpenAIRE |
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