A NEW METHOD FOR THE PREPARATION OF 2,3-DIARYL-1,1-DIFLUORO-1,3-BUTADIENES
摘要:
Reactions of 1-trifluoromethyl-1,2-diarylvinyl sulfones 3 with aryllithium afforded aryl substituted adduct 4. Bromination of 4 with NBS, followed by debromofluorination with Mg, provided 2,3-diaryl- 1, 1-difluoro-1,3-butadienes (6) in good yields.
Novel synthesis of 1-aryl-1-trifluoromethylallenes
摘要:
3,3-Bis(phenylthio)-1, 1, 1, 2,2-pentaflnorobutane I was reacted with aryllithium reagents (6 equiv) in ether at low to room temperature for 1-6 h to provide 2-aryl-1, 1, 1-trifluoro-3-phenylthio-2-butene 2 in 80-96% yields. Bromination of 2 with NBS in acetonitrile at reflux for 1-7 h afforded the corresponding allylic bromides 3 in 61-96% yields. Treatment of 3 with MCPBA (1.5 equiv) in methylene chloride at reflux temperature for 1-12 h resulted in the formation of 1-aryl-1-trifluoromethylallenes 4 in 74-96% yields. (c) 2005 Elsevier Ltd. All rights reserved.