A novel copper-catalyzed sulfurdioxideanion incorporation cascade for the synthesis of 1-thiaflavanone sulfones has been disclosed using rongalite as an economic and safe sulfone source. A series of 1-thiaflavanone sulfones were synthesized from easily prepared 2′-iodochalcone derivatives in excellent yields. This transformation proceeds through consecutive formation of two C–S bonds, which is the
process for the formation of diethyl 2-aryl-3,4-dihydro-4-oxo-1,1(2H)-naphthalenedicarboxylate is described by using a combination of Michael addition and copper-catalyzed α-arylation of malonicacidderivatives. The protocol worked well for a variety of 1-(2-iodoaryl)enones and displayed great functional group compatibility. Michael addition - copper - catalysis - cascade reactions- α-arylation
Domino Synthesis of Thioflavones and Thioflavothiones by Regioselective Ring Opening of Donor–Acceptor Cyclopropane Using In-Situ-Generated Thiolate Anions
作者:Nallappan Sundaravelu、Govindasamy Sekar
DOI:10.1021/acs.orglett.9b02210
日期:2019.9.6
A copper-catalyzed intramolecular ring opening of donor-acceptor cyclopropane is developed for the synthesis of 3-alkyl-carbonated thioflavones and further extended to 3-alkyl-carbonated thioflavothione, using xanthate as a sulfur surrogate. This reaction proceeds through thiolate formation/ring opening/Krapcho decarboxylation, followed by hydrogen abstraction, to give thioflavanone, which is further