1069128-02-4Relevant academic research and scientific papers
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 NaHSO 4 /SiO 2 and Na 2 CO 3 /SiO 2
Aoyama, Tadashi,Hayakawa, Mamiko,Kosuge, Masayuki,Nakaoka, Kyohei,Ouchi, Akihiko
supporting information, p. 2572 - 2578 (2019/06/08)
A four-step synthesis of benzo- and naphthothiophenes that have biological importance and application in material science was integrated into a one-pot reaction by using silica gel-supported acid and base reagents, NaHSO 4 /SiO 2 and Na 2 CO 3 /SiO 2. The supported reagents provided acid and base environments on the surface of the supports without neutralization and worked separately in the same medium. The four-step reaction comprises (i) deacetylation of 3-halo-2,4-pentanediones to α-halo ketones, (ii) deacetylation of S -aryl thioacetates to arenethiols, (iii) coupling of α-halo ketones and arenethiols to give α-sulfanyl ketones, and (iv) cyclization of sulfanyl ketones to benzo- and naphthothiophenes. The steps (i) and (iii) proceeded by Na 2 CO 3 /SiO 2, and (ii) and (iv) by NaHSO 4 /SiO 2. The four-step 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.
One-pot synthesis using the supported reagent system Na2CO 3/SiO2-PPA/SiO2: Synthesis of Benzo[b]thiophenes and naphthothiophenes
Aoyama, Tadashi,Orito, Mami,Takido, Toshio,Kodomari, Mitsuo
body text, p. 2089 - 2099 (2009/04/03)
A simple and efficient method has been developed for the synthesis of benzo[b]thiophenes and naphtho[2,l-6]thiophenes from arenethiols and α-halo ketones using Na2CO3/SiO2-PPA/ SiO2. Reaction of a-halo ketones with arenethiols is promoted by Na2CO3/SiO2 to afford α-sulfanyl ketones, which cyclize in the presence of PPA/SiO2 to give the corresponding thiophene-fused arenes in one-pot. The reaction using α-bromo acetals instead of α-halo ketones also gave the corresponding naphtho[2,l-b] thiophenes via a three-step reaction in one-pot. Thieme Stuttgart.
