分子内Tropylium离子介导的呋喃开环反应和萘[1,2- a ] azulene衍生物的X射线研究新颖合成苯并丙酮类似物萘[ a ] azulenes。
摘要:
由2-(5-)合成萘[1,2- a ] azulene(8),萘[2,1- a ] azulene(13)和萘[2,3- a ] azulene(18)的苯丙酮丙酮类似物。甲基-2-呋喃基)-1-对苯二甲酰基(7),1-(5-甲基-2-呋喃基)-2-对苯二甲酰基萘(12)和2-(5-甲基-2-呋喃基)-3-对苯二甲酰基萘(17)。合成方法基于对呋喃离子的分子内亲电攻击而引起的呋喃开环反应。萘[1,2- a ] az杂烯衍生物的单晶X射线研究(8)表明,其四环体系的平面度与苯并[ c ]菲(四螺旋)相似。在晶体中发现了一个中心对称相关的二聚体结构,就像羧酸分子一样,但通过C O···H-C氢键。还发现减少了七元环中的键长交替。
A facile, one-pot synthesis of β-(benz[a]azulen-10-yl)-α,β-unsaturatedketones from the corresponding o-(2-furyl)cycloheptatrienylbenzenes is reported. A mechanism involving a novel ring-opening cyclisation reaction by the intramolecular attack of the tropylium ion to the 2-position of the furan ring is proposed.
据报道,由相应的邻-(2-呋喃基)环庚三烯基苯可方便地一锅合成β-(苯并[ a ] azulen-10-基)-α,β-不饱和酮。提出了一种涉及新的开环环化反应的机理,该环化反应是由对苯二甲基离子的分子内攻击呋喃环的2位引起的。
Novel and facile synthesis of β-(4-azuleno[1,2-b]thienyl)- and β-(4-azuleno[2,1-b]thienyl)-α,β-unsaturated ketones by intramolecular tropylium ion-mediated furan ring-opening reaction
The novel and efficient methods for the synthesis of β-(4-azuleno[1,2-b]thienyl)-α,β-unsaturatedketones (1) and β-(4-azuleno[2,1-b]thienyl)-α,β-unsaturatedketones (2) have been described. Refluxing the dichloromethane solutions of 2-tropylio-3-(2-furyl)thiophene tetrafluoroborates (3) or 3-tropylio-2-(2-furyl)thiophene tetrafluoroborates (4) afforded (1) and (2), respectively, in moderate yields
合成β-(4-azuleno [1,2- b ]噻吩基)-α,β-不饱和酮(1)和β-(4-azuleno [2,1- b ]噻吩基)的新颖有效方法已经描述了-α,β-不饱和酮(2)。回流2-对甲苯基-3-(2-呋喃基)噻吩四氟硼酸酯(3)或3-对甲苯基-2-(2-呋喃基)噻吩四氟硼酸酯(4)的二氯甲烷溶液,分别得到(1)和(2)。中等产量。该反应涉及分子内的yl离子介导的呋喃开环反应。
An efficient novel synthesis of β-(azuleno[1,2-b]benzothienyl)- and β-(azuleno[2,1-b]benzothienyl)-α,β-unsaturated ketones by the tropylium ion-mediated intramolecular furan ring-opening reaction and X-ray investigation of methyl ketone derivative1
Intramolecular reaction of 2-tropylio-3-(5-substituted 2-furyl)benzothiophenes (3), prepared from the corresponding 2-cycloheptatrienyl-3-(5-substituted 2-furyl)benzothiophenes (2), afforded the beta-(azuleno[1,2-b]benzothienyl)-alpha,beta-unsaturated ketones (4), which are otherwise difficult to obtain, in moderate yields. The reaction involves a ring-opening process of the furan ring by intramolecular
Novel and efficient one-pot synthesis of azuleno[1,2-<i>b</i>]-benzothiophenic enones from the corresponding 2-cycloheptatrientyl-3-(2-furyl)benzothiophenes
2-Cycloheptatrienyl-3-(2-furyl)benzothiophenes, which are prepared by Stille coupling reaction of 2-cyclo-heptatrienyl-3-bromobenzothiophene with the 5-substituted 2-trimethylstannylfurans, react with triphenylmethyl tetrafluoroborate to give the correspondingazuleno[1,2-b]benzothiophenic enones in excellent yields.