Electrochemical Cross‐Dehydrogenative Coupling between Phenols and β‐Dicarbonyl Compounds: Facile Construction of Benzofurans
作者:Yandong Wang、Bailin Tian、Mengning Ding、Zhuangzhi Shi
DOI:10.1002/chem.201904750
日期:2020.4
required to facilitate the dehydrogenation and dehydration processes. The key factor in the success was the use of n Bu 4 NBF 4 as the electrolyte and hexafluoroisopropanol (HFIP) as the solvent, which play key roles in the cyclocondensation step. This electrolysis is scalable and can be used as a keystep in drug synthesis. On the basis of the several experimental results, the mechanism, particularly
制备电化学合成是建立绿色可持续工艺的理想方法。与传统的化学合成方法相比,有机化学策略的主要优点是避免了试剂浪费和温和的反应条件。在此,已经开发了在不分开的电解条件下,酚与β-二羰基化合物之间的分子间交叉脱氢偶联(CDC),以构建各种苯并呋喃。过渡金属或外部化学氧化剂都不需要以促进脱氢和脱水过程。成功的关键因素是使用n Bu 4 NBF 4作为电解质,使用六氟异丙醇(HFIP)作为溶剂,它们在环缩合步骤中起关键作用。这种电解是可扩展的,可以用作药物合成中的关键步骤。
Condensed heteroaromatic ring systems. XXIV. Palladium-catalyzed cyclization of 2-substituted phenylacetylenes in the presence of carbon monoxide
The palladium-catalyzed reaction of 2-alkynylanilines and 2-alkynylphenols in the presence of carbon monoxide and methanol under basic conditions gave the sequential cyclization / carbonylation products, methyl 2-substituted indole and benzo[b]-furan-3-carboxylates. Similar reaction of 2-alkynylbenzamides gave 3-alkylidenisoindole derivatives.
在碱性条件下,在一氧化碳和甲醇存在下,钯催化的2-炔基苯胺和2-炔基苯酚的反应,依次得到环化/羰基化产物,2-甲基取代的吲哚和苯并[ b ]-呋喃-3-羧酸酯。2-炔基苯甲酰胺的类似反应得到3-亚烷基亚异吲哚衍生物。
A Concise Route to Dihydrobenzo[<i>b</i>]furans: Formal Total Synthesis of (+)-Lithospermic Acid
作者:Joshua Fischer、G. Paul Savage、Mark J. Coster
DOI:10.1021/ol201130h
日期:2011.7.1
benzofuran reduction (Mg, MeOH, NH4Cl) provides a convergent and modular synthetic route to trans-2-aryl-2,3-dihydrobenzo[b]furan-3-carboxylates, which are a structural feature of numerous biologically active natural products. This versatile strategy was applied to the formal total synthesis of the anti-HIV natural product (+)-lithospermic acid.
Sonogashira偶联,Pd(II)催化的羰基环化和苯并呋喃还原(Mg,MeOH,NH 4 Cl)的序列为反式-2-芳基-2,3-二氢苯并[ b ]呋喃提供了一种收敛的模块化合成途径。-3-羧酸盐,是许多具有生物活性的天然产物的结构特征。这种多用途的策略适用于抗HIV天然产物(+)-紫精酸的正式全合成。
Application of phase-vanishing method with CO gas evolution to carbonylation reactions
作者:Yusuke Adachi、Hiroshi Matsubara
DOI:10.1016/j.jfluchem.2018.10.006
日期:2018.12
Although carbonmonoxide (CO) is considered a practical source of the carbonyl functionality in various compounds, handling CO gas is difficult. The phase-vanishing (PV) method, using highly fluorinated solvents as the phase screen, was thus employed, in which CO was evolved for use in organic synthesis. An H-shaped reactor bearing two reaction chambers was employed. In the first chamber, CO was efficiently
Hypervalent Iodine Oxidation of Flavanones: A New Synthesis of Methyl 2-Aryl-2,3-dihydrobenzofuran-3-carboxylates by 1,2-Aryl Shift
作者:Om Prakash、Madan P. Tanwar
DOI:10.1246/bcsj.68.1168
日期:1995.4
Flavanones (1), on oxidation with (diacetoxyiodo)benzene-sulfuric acid (DIB–H2SO4) or (hydroxy)tosyloxy)iodo)benzene (HTIB) in trimethyl orthoformate, undergo facile ring contraction by 1,2-aryl shift, thereby yielding methyl 2-aryl-2,3-dihydrobenzofuran-3-carboxylates (4) as major products (40—80%). cis-3-Methoxyflavanones (5) and flavones (3) are the minor products formed in variable ratios.