Synthesis of Functionalized Diaryldiazenes by Formal [3+3] Cyclizations of 1,3-Bis(silyloxy)-1,3-butadienes with 2-Aryldiazenyl-3-silyloxy-2-en-1- ones
The formal [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 2-aryldiazenyl-3-silyloxy- 2-en-1-ones afforded a variety of functionalized diaryl-diazenes.
Diversity-Oriented Synthesis of Functionalized 1-Aminopyrroles by Regioselective Zinc Chloride-Catalyzed, One-Pot ‘Conjugate Addition/Cyclization’ Reactions of 1,3-Bis(silyl enol ethers) with 1,2-Diaza-1,3-butadienes
convenient one-pot process, the easily accessible 1,2-diaza-1,3-butadienes and 1,3-bis(silyl enolethers) are converted into the previously unknown functionalized 1-aminopyrroles and 1-amino-4,5,6,7-tetrahydroindoles. The domino reaction proceeds through a zinc chloride-catalyzed ‘conjugate addition/cyclization’ sequence.
Regioselective synthesis of 3-(methylthio)phenols by formal [3+3]-cyclocondensations of 3-oxo-bis(methylthio)ketenacetals with 1,3-bis(trimethylsilyloxy)-1,3-butadienes and 1,3-dicarbonyl dianions
The cyclization of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-oxo-bis(methylthio)ketenacetals afforded 3-(methylthio)phenols containing an acyl or ester substituent located at position 2. The cyclization of free 1,3-dicarbonyl dianions with 3-oxo-bis(methylthio)ketenacetals resulted in the formation of regioisomeric products containing an acyl group located at position 6.
Synthesis of Functionalized Biaryls Based on a Heck Cross-Coupling-[3+3] Cyclization Strategy
作者:Peter Langer、Gerson Mroß、Helmut Reinke
DOI:10.1055/s-2008-1072654
日期:——
6-Arylsalicylates were regioselectively prepared by formal [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 1-aryl-3-ethoxyprop-2-en-1-ones which are available by Heck reaction of benzoyl chlorides with ethylvinyl ether. In this context, the first [3+3] cyclizations of brominated substrates are reported.
The formal [3+3] cyclization of 1,3-bis(silyloxy)buta-1,3-dienes with 1-aryl-3-ethoxyprop-2-en-1-ones, available by Heck reaction of benzoyl chlorides with ethyl vinyl ether, afforded a variety of 6-arylsalicylates. The reaction of the products with concentrated sulfuric acid resulted in the formation of fluorenones. 6-Alkylsalicylates were prepared by cyclization of 1,3-bis(silyloxy)buta-1,3-dienes