Visible-Light-Promoted Oxo-Sulfonylation of Ynamides with Sulfonic Acids
作者:Lu Wang、Chengrong Lu、Yanni Yue、Chao Feng
DOI:10.1021/acs.orglett.9b00733
日期:2019.5.17
A visible-light-promoted oxo-sulfonylation of ynamides with sulfonicacids is reported, giving rise to a collection of functionalized α-sulfonylated amides in a straightforward manner. The reaction proceeds sequentially through a cascade of electrophilic addition and photoinduced sulfonyl radical-sustained skeleton rearrangement. The high atom economy, mild reaction conditions, and wide substrate scope
Hydrative Aminoxylation of Ynamides: One Reaction, Two Mechanisms
作者:Alexandre Pinto、Daniel Kaiser、Boris Maryasin、Giovanni Di Mauro、Leticia González、Nuno Maulide
DOI:10.1002/chem.201706063
日期:2018.2.16
Organic synthesis boasts a wide array of reactions involving either radical species or ionic intermediates. The combination of radical and polar species, however, has not been explored to a comparable extent. Herein we present the hydrative aminoxylation of ynamides, a reaction which can proceed by either a polar-radical crossover mechanism or through a rare cationic activation. Common to both processes
有机合成拥有涉及自由基物质或离子中间体的广泛反应。然而,自由基和极性物种的结合尚未得到相当程度的探索。在这里,我们提出了 ynamides 的水合氨氧基化反应,该反应可以通过极性-自由基交叉机制或通过罕见的阳离子活化进行。这两个过程的共同点是持久自由基 TEMPO 及其氧化的氧代铵衍生物TEMPO+ 的多功能性。通过实验和深入的 DFT 计算阐明了这些过程的独特机制。
Unusual mechanisms in Claisen rearrangements: an ionic fragmentation leading to a <i>meta</i>-selective rearrangement
作者:Boris Maryasin、Dainis Kaldre、Renan Galaverna、Immo Klose、Stefan Ruider、Martina Drescher、Hanspeter Kählig、Leticia González、Marcos N. Eberlin、Igor D. Jurberg、Nuno Maulide
DOI:10.1039/c7sc04736c
日期:——
A mechanistic investigation of the acid-catalysed redox-neutral oxoarylation reaction of ynamides using electrospray ionisation mass-spectrometry (ESI-MS) and quantum chemical calculations (DFT and MP2) is presented. This study reveals the diversity of pathways and products available from an otherwise deceptively simple-looking, classical transformation: fragmentation, an unusual meta-arylation and
A Brønstedacid catalyzed redox arylation of ynamides that employs aryl sulfoxides as the arylating agents is reported. This metal‐free transformation proceeds at room temperature and efficiently affords α‐arylated oxazolidinones in a redox‐neutral, atom‐economic fashion.
On the formation of seven-membered rings by arene-ynamide cyclization
作者:Bogdan R. Brutiu、Wilhelm Andrei Bubeneck、Olivera Cvetkovic、Jing Li、Nuno Maulide
DOI:10.1007/s00706-018-2320-x
日期:2019.1
AbstractA Brønsted acid-catalyzed selective arene-ynamide cyclization is described. This reaction proceeds via a keteniminium intermediate and enables the preparation of seven-memberedring enamide products. Mechanistic studies uncover an unusual product inhibition behavior. Graphical abstract