Integration of a Four-Step Reaction into One-Pot under the Coexistence of Silica-Gel-Supported Acid and Base Reagents: Synthesis of Benzo- and Naphthothiophenes Using NaHSO4/SiO2 and Na2CO3/SiO2
reaction proceeded efficiently by introduction of starting materials and reagents in a single reaction vessel. The starting materials were very easy to handle and unpleasant smell of aryl thiols that were used in conventional methods could be avoided. Novel thirty-nine benzo- and naphthothiophenes were synthesized by this method in excellent to fair yields. A four-step synthesis of benzo- and naphthothiophenes
One-Pot Synthesis of Benzo[<i>b</i>]thiophenes and Naphtho[2,1-<i>b</i>]thiophenes in the Presence of Acidic and Basic Supported Reagents
作者:Tadashi Aoyama、Toshio Takido、Mitsuo Kodomari
DOI:10.1055/s-2005-918928
日期:——
A simple and efficient method has been developed for the synthesis of benzo[b]thiophenes and naphtho[2,1-b]thiophenes from aryl thiols and α-halo ketones by using an acid- and a base-supported reagent system, Na 2 CO 3 /SiO 2 -PPA/SiO 2 . Reaction of α-halo ketones with aryl thiols is promoted by Na 2 CO 3 /SiO 2 to afford α-phenylthio ketones, which cyclizes in the presence of PPA/SiO 2 to give the
One-Pot Synthesis Using the Supported Reagent System Na<sub>2</sub>CO<sub>3</sub>/SiO<sub>2</sub>-PPA/SiO<sub>2</sub>: Synthesis of Benzo[<i>b</i>]thiophenes and Naphthothiophenes
method has been developed for the synthesis of benzo[ B]thiophenes and naphtho[2,1- B]thiophenes from arenethiols and α-halo ketones using Na 2 CO 3 /SiO 2 -PPA/SiO 2 . Reaction of α-halo ketones with arenethiols is promoted by Na 2 CO 3 /SiO 2 to afford α-sulfanyl ketones, which cyclize in the presence of PPA/SiO 2 to give the corresponding thiophene-fused arenes in one-pot. The reaction using α-bromo acetals
开发了一种简单有效的方法,用于使用 Na 2 CO 3 /SiO 2 -PPA/SiO 2 从芳硫醇和α-卤代酮合成苯并[B]噻吩和萘并[2,1-B]噻吩。Na 2 CO 3 /SiO 2 促进α-卤代酮与芳烃硫醇反应生成α-硫烷基酮,在PPA/SiO 2 存在下环化生成相应的噻吩稠合芳烃一锅法。使用α-溴缩醛代替α-卤代酮的反应也通过一锅三步反应得到相应的萘并[2,1-B]噻吩。