分子内trop离子介导的新型且简便的合成β-(4-azuleno [1,2- b ]噻吩基)和β-(4-azuleno [2,1- b ]噻吩基)-α,β-不饱和酮呋喃开环反应
摘要:
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。
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。
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