5-Endo-dig iodocyclisations of alk-3-yn-1,2-diols 4, followed by in situ dehydration, lead to good yields of beta-iodofurans 5, which can subsequently be converted into a wide range of derivatives 6-13, using transition metal-catalysed coupling reactions or halogen-metal exchange.
Brønsted Acid-Catalyzed Cycloisomerization of But-2-yne-1,4-diols with or without 1,3-Dicarbonyl Compounds to Tri- and Tetrasubstituted Furans
作者:Srinivasa Reddy Mothe、Sherman Jun Liang Lauw、Prasath Kothandaraman、Philip Wai Hong Chan
DOI:10.1021/jo301093f
日期:2012.8.17
efficiently from cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds is described. By taking advantage of the orthogonal modes of reactivity of the alcoholic substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. At roomtemperature, p-TsOH·H2O-mediated tandem alkylation/cycloisomerization of the propargylic
Oxidative Cross-Coupling of Allenyl Ketones and Organoboronic Acids: Expeditious Synthesis of Highly Substituted Furans
作者:Ying Xia、Yamu Xia、Rui Ge、Zhen Liu、Qing Xiao、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201400500
日期:2014.4.7
Allenylketones are employed as coupling partners in palladium‐catalyzed oxidative cross‐coupling reactions with organoboronicacids. This reaction constitutes an efficient methodology for the synthesis of highlysubstitutedfuran derivatives. Palladium‐carbene migratory insertion is proposed as the key step in this transformation.
A base-catalysed [3 + 2] cycloaddition reaction of propargylamines and aldehydes for the regiospecific synthesis of substituted furans under metal-free conditions is developed. Propargylamines are used as allenyl anion equivalents and applied in [3 + 2] cycloaddition reactions with aldehydes. Various substituted furans are provided up to 91% yield for 28 examples.
Selenium Dioxide‐Promoted Regioselective Synthesis of Multi‐Substituted Furans from Terminal Alkynes and Aldehydes
作者:Yafeng Liu、Fengkai Sun、Zhenyu An、Man Miao、Xin Guo、Chonglong Li
DOI:10.1002/adsc.202300964
日期:2024.1.9
A SeO2-mediated regioselective synthesis of multi-substituted furans has been achieved through intermolecular cyclization of terminalalkynes with aldehydes. The developed methodology used commercially available starting materials and afforded various 2,3,5-triarylfurans.