A facile approach to highly functional trisubstituted furans via intramolecular Wittig reactions
作者:Ko-Wei Chen、Siang-en Syu、Yeong-Jiunn Jang、Wenwei Lin
DOI:10.1039/c0ob00912a
日期:——
An efficient and mild synthesis of trisubstituted furans, starting from α,β-unsaturated ketones, tributylphosphine, and acyl chlorides, is described. The strategy employs the intramolecular Wittig protocol as a key step to install the crucial furan ring, leading to a wide variety of highly functional furans in one step.
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.