通过一锅直接法在室温下通过AlCl 3介导的α-氧杂环丁烯二硫缩醛和1,4-苯并/萘醌的多米诺环化反应制备2,3-二取代的苯并/萘并[ b ]呋喃
摘要:
在室温下存在氯化铝的情况下,通过α-氧杂环丁烯二硫缩醛和1,4-苯并/萘醌的多米诺环化反应,获得了一种通用且方便的一锅直接方法,用于2,3-二取代的苯并/萘并[ b ]呋喃。该方案代表了在温和的反应条件下,从容易生存的起始原料中以极高的收率非常容易,直接,迅速地进入高度取代的苯并/萘并[ b ]呋喃。
Unexpected Hydrobromic Acid-Catalyzed CC Bond-Forming Reactions and Facile Synthesis of Coumarins and Benzofurans Based on Ketene Dithioacetals
作者:Hongjuan Yuan、Mang Wang、Yingjie Liu、Lili Wang、Jun Liu、Qun Liu
DOI:10.1002/chem.201002107
日期:2010.12.3
Hydrobromic acid was found to be a unique catalyst in CC bond‐forming reactions with ketene dithioacetals. Distinctly different from other acids (including Lewis and Brønsted acids), the remarkable catalytic performance of hydrobromic acid in catalytic amounts was observed in the “acid”‐catalyzed reactions of readily available functionalized ketene dithioacetals 1 with various electrophiles. Under
氢溴酸被发现是在C独特催化剂与烯酮二硫C键形成反应。与其他酸(包括路易斯酸和布朗斯台德酸)明显不同,氢溴酸在催化量上的显着催化性能在易于获得的官能化乙烯酮二硫缩醛1与各种亲电试剂的“酸”催化反应中观察到。在0.1当量的氢溴酸的催化下,1与羰基化合物2 a – l的反应生成多官能化的戊-1,4-二烯3或共轭二烯4产量高到极好。该反应在乙烯酮二硫缩醛1和羰基化合物2上均具有宽范围的取代基。这种有效的CC键形成方法的应用是在温和的,无金属的条件下,通过氢溴酸1与水杨醛2 m - o和对苯醌6 a - d的反应生成香豆素5和苯并呋喃7。, 分别。根据抗衡离子的性质,形成了一种新的反应性物种,即一种硫稳定的碳鎓叶立德,这被提议作为氢溴酸独特催化的关键中间体。
Copper(II) Bromide/Boron Trifluoride Etherate-Cocatalyzed Cyclization of Ketene Dithioacetals and p-Quinones: a Mild and General Approach to Polyfunctionalized Benzofurans
作者:Yingjie Liu、Mang Wang、Hongjuan Yuan、Qun Liu
DOI:10.1002/adsc.200900809
日期:2010.3.22
general method for catalytic synthesis of polyfunctionalized benzofurans with the advantages of readily available starting materials, cheap catalysts, mild reaction conditions, good yields and wide range of synthetic potential for the benzofuran products. Further transformations of the resulting benzofurans to 2‐aminobenzofurans and benzofuro[2,3‐d]pyrimidine derivatives are also investigated.
One-pot straightforward approach to 2,3-disubstituted benzo/naphtho[b]furans via domino annulation of α-oxoketene dithioacetals and 1,4-benzo/naphthoquinone mediated by AlCl3 at room temperature
versatile and convenient one-pot direct approach to 2,3-disubstituted benzo/naphtho[b]furans via domino annulation of α-oxoketene dithioacetals and 1,4-benzo/naphthoquinone has been achieved in the presence of aluminium chloride at room temperature. This protocol represents an extremely simple, straightforward and rapid entry to highly substitutedbenzo/naphtho[b]furans in good yields from easily viable
在室温下存在氯化铝的情况下,通过α-氧杂环丁烯二硫缩醛和1,4-苯并/萘醌的多米诺环化反应,获得了一种通用且方便的一锅直接方法,用于2,3-二取代的苯并/萘并[ b ]呋喃。该方案代表了在温和的反应条件下,从容易生存的起始原料中以极高的收率非常容易,直接,迅速地进入高度取代的苯并/萘并[ b ]呋喃。