Working three shifts: Polyconjugated δ‐diketones are formed stereoselectively in high yields by the gold‐catalyzed rearrangement of 1,6‐diyn‐3‐yl esters. This cascade involves a 1,3‐sigmatropic acyloxy shift, a 5‐exo‐dig cyclization of the resulting allenyne, and an unprecedented 1,5‐sigmatropic shift of an acyl fragment. The usefulness of the products was shown by an efficient acid‐catalyzed transformation
Cobalt-Catalyzed Cyclization/Hydroboration of 1,6-Diynes with Pinacolborane
作者:Qiang Huang、Meng-Yang Hu、Shou-Fei Zhu
DOI:10.1021/acs.orglett.9b02873
日期:2019.10.4
Herein, we report a protocol for cyclization/hydroboration of 1,6-diynes with pinacolborane using a cobalt catalyst generated in situ from a Co(II)-phenanthroline complex, tetrabutylammonium fluoride, and pinacolborane. This protocol, which features good functional group tolerance, a broad substrate scope, and excellent stereoselectivity, enables the synthesis of useful cyclic 1,3-dienylboron compounds
Base-Induced Cyclization of Derivatives of Bispropargylated Acetic Acid to m-Toluic Acid
作者:Tammar Ali、Thorsten Heidelberg、Rusnah Hussen
DOI:10.1055/s-0034-1380513
日期:——
A base-inducedcyclization reaction of 1,1-bispropargyls has been examined. Alkali treatment of 2,2-bispropynyl acetic acid derivatives in aqueous ethanol mostly provided 3-methylbenzoic acid. Investigations on substituent effects indicate the requirement of an electron-withdrawing group causing CH acidity and the center of the dipropargylic structure. Besides, an intramolecular hydrogen transfer causing
A Golden Synthetic Approach to 2-(1H-Pyrrol-1-yl)anilines and Pyrrolo[1,2-a]quinoxalines through a Gold Carbene Intermediate
作者:Nurettin Menges、Volkan Tasdemir、Hasan Genç
DOI:10.1055/a-2159-9400
日期:2024.4
The pyrrolo[1,2-a]quinoxaline skeleton has significant potential for many biological and optical applications. Hence, in this study, unconjugated ynone derivatives were treated with 1,2-diaminoarenes in a gold-catalyzed cyclization to give 2-(1H-pyrrol-1-yl)anilines, which are valuable starting materials, and pyrrolo[1,2-a]quinoxalines by a one-pot and single-step approach. A reaction mechanism for the
吡咯并[1,2-a]喹喔啉骨架在许多生物和光学应用中具有巨大的潜力。因此,在本研究中,在金催化环化中用 1,2-二氨基芳烃处理非共轭炔酮衍生物,得到 2-(1 H-吡咯-1-基)苯胺(这是有价值的起始原料)和吡咯[1,通过一锅单步方法制备2- a ]喹喔啉。提出了以关键金卡宾中间体为特征的吡咯并[1,2- a ]喹喔啉骨架形成的反应机理。另一方面,2-(1H-吡咯-1-基)苯胺的C-2位甲基被SeO 2氧化,得到吡咯并[1,2- a ]喹喔啉骨架,得到14 种不同的吡咯并[1,2- a ]喹喔啉衍生物。
Plouin,D.; Glenat,R., Comptes Rendus des Seances de l'Academie des Sciences, Serie C: Sciences Chimiques, 1972, vol. 274, p. 2084 - 2087