An expedient route to substituted furans via olefin cross-metathesis
作者:Timothy J. Donohoe、John F. Bower
DOI:10.1073/pnas.0913466107
日期:2010.2.23
of highly substituted derivatives are essential to medicinal chemistry. Here we show that the olefin CM reaction, in combination with an acid cocatalyst or subsequent Heck arylation, provides a concise and flexible entry to 2,5-di- or 2,3,5-tri-substituted furans. These cascade processes portend further opportunities for the regiocontrolled preparation of other highly substituted aromatic and heteroaromatic
烯烃交叉复分解 (CM) 反应广泛用于有机化学,是选择性合成差异取代烯烃产物的有效方法。令人惊讶的是,尚未报道将这一非凡的过程整合到芳香族和杂芳香族构建策略中的努力。这种结构代表了大多数小分子药物化合物的关键要素;高度取代衍生物的受控制备方法对于药物化学是必不可少的。在这里,我们展示了烯烃 CM 反应与酸助催化剂或随后的 Heck 芳基化相结合,为 2,5-二-或 2,3,5-三-取代呋喃提供了简洁而灵活的入口。
Production of Polyester Blend of Poly(3-hydroxybutyrate-<i>co</i>-4-hydroxybutyrate) and Poly(3-hydroxyalkanoate) with Saturated and Unsaturated Monomers from 4-Hydroxybutyric Acid by<i>Chromobacterium</i>sp.
Chromobacterium sp. isolated from a river soil produced a polyester blend of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)(P(3HB-co-4HB)) and poly(3-hydroxyalkanoate) (P(3HA)) consisting of both saturated 3-hydroxyalkanoic acid(3HA) units of even carbon number from C4 to C14 and unsaturated 3HA units of carbon number C12 and C14, when 4-hydroxybutyric acid(4HBA) was fed as the sole carbon sources.
Ruthenium-catalysed conversion of 1,4-alkynediols into pyrroles
作者:Simon J. Pridmore、Paul A. Slatford、Aurélie Daniel、Michael K. Whittlesey、Jonathan M.J. Williams
DOI:10.1016/j.tetlet.2007.05.070
日期:2007.7
Various 1,2,5-substituted pyrroles have been synthesised from 1,4-alkynediols using a ruthenium catalysed isomerisation to give the corresponding 1,4-dicarbonyl compounds, which undergo in situ cyclisation to pyrroles in the presence of amine. (C) 2007 Published by Elsevier Ltd.
Synthesis of furans, pyrroles and pyridazines by a ruthenium-catalysed isomerisation of alkynediols and in situ cyclisation
作者:Simon J. Pridmore、Paul A. Slatford、James E. Taylor、Michael K. Whittlesey、Jonathan M.J. Williams
DOI:10.1016/j.tet.2009.06.108
日期:2009.10
Alkyne-1,4-diols are readily available substrates which are isomerised to 1,4-diketones using Ru(PPh3)(3)(CO)H-2/xantphos as a catalyst. In situ cyclisation into furans, pyrroles and pyridazines has been achieved under suitable conditions. (C) 2009 Elsevier Ltd. All rights reserved.
2,5-Disubstituted furans from 1,4-alkynediols
作者:Simon J. Pridmore、Paul A. Slatford、Jonathan M.J. Williams
DOI:10.1016/j.tetlet.2007.05.069
日期:2007.7
1-4-Alkynediols serve as readily available starting materials for isomerisation to 1,4-diketones, which can be converted in situ into the corresponding furans by acid-catalysed dehydration. A range of 2,5-disubstituted furans was prepared using the ruthenium-based catalyst Ru(PPh3)(3)(CO)H-2 with Xantphos at 1 mol % loading. (C) 2007 Published by Elsevier Ltd.