Synthesis of Stilbene-Quinone Hybrids through Heck Reactions in PEG-400Financial supports from Brazilian agencies CNPq (Project 442337/2014-0), FAPERJ (Project E-26/111.358/2014), and UFRJ are acknowledged.
Received: 17 May 2017
Accepted after revision: 17 July 2017
28 August 2017 (eFirst)
Dedicated to Professor Paulo R. R. Costa on the occasion of his 67th birthday
Styrenes were coupled with 3-iodolawsone in PEG-400 at 90 °C, leading stereoselectively to (E)-stilbene-quinone hybrids through Heck reactions. The best reaction conditions were found to be the use of NaOH (3 equiv) and 10 mol% of palladium acetate at 90 °C for 15 minutes. The chemical yields of the Heck reactions using styrenes with electron-withdrawing groups (65–98%) were greater than styrenes bearing electron-donating groups (7–32%) on the aromatic ring. In particular, the chemical yields of Heck reactions involving nitrostyrenes were the best ones observed.