Functionalization of 1-hydroxymethyl-4,5-dihalopyridazin-6-ones via a retro-ene reaction with some nucleophiles gave regioselectively only 5-halo-4-substitutedpyridazin-6-ones.
Pyridazines. Part 34: Retro-ene-assisted palladium-catalyzed synthesis of 4,5-disubstituted-3(2H)-pyridazinones
作者:Eddy Sotelo、Alberto Coelho、Enrique Raviña
DOI:10.1016/s0040-4039(03)01029-3
日期:2003.6
The efficient one-pot bis-functionalization of the 4,5-positions of the 3-pyridazinone ring has been performed using Suzuki. Sonogashira and Stille cross-coupling reactions assisted by a retro-ene fragmentation. This route allows access in a shorter synthetic sequence to several pharmacologically useful 3(2H)-pyridazinones. (C) 2003 Elsevier Science Ltd. All rights reserved.
Pyridazines. Part 35:Traceless Solid PhaseSynthesis of 4,5- and 5,6-Diaryl-3(2<i>H</i>)-pyridazinones
作者:Enrique Raviña、Eddy Sotelo
DOI:10.1055/s-2003-39882
日期:——
A new method for the traceless solid phase synthesis of 3(2H)-pyridazinones has been developed employing dihydropyran-functionalized resin. The procedure has permitted the preparation of several diarylpyridazinones through a Suzuki cross-coupling reaction and cleavage conditions that promoted a retro-ene fragmentation.