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.
Chelation-control in the formal [3+3] cyclization of 1,3-bis-(silyloxy)-1,3-butadienes with 1-hydroxy-5-silyloxy-hex-4-en-3-ones. One-pot synthesis of 3-aryl-3,4-dihydroisocoumarins
The [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 1-hydroxy-5-silyloxy-hex-4-en-3-ones resulted in the one-pot formation of 3-aryl-3,4-dihydroisocoumarins. The reactions proceeded by regioselective cyclization to give 6-(2-aryl-2-chloroethyl)salicylates, which underwent a silica gel-mediated lactonization. The cyclizations of protected 1-amino-5-silyloxy-hex-4-en-3-ones proved to be not
Chelation Control in the [3 + 3] Annulation Reaction of Alkoxy-Substituted 1,1-Diacylcyclopropanes with 1,3-Bis(trimethylsilyloxy)-1,3-butadienes. Diversity-Oriented Synthesis of Isochromanes
chelation-controlled [3 + 3] cyclization/cyclopropane opening reactions of 1-trimethylsilyloxy-1,3-butadienes with benzyloxy- or methoxy-substituted 1,1-diacylcyclopropanes. A number of benzyloxy-substituted derivatives were transformed into isochromanes by deprotection and subsequent cyclization. Mixed chromanes−isochromanes were prepared starting with 1,3-bis(silyloxy)-1,3-butadienes containing a remote
Regioselective Synthesis of 6-[Chloro(difluoro)methyl]salicylates by [3+3] Cyclocondensations of 1,3-Bis(trimethylsilyloxy)buta-1,3-dienes with 1-Chloro-1,1-difluoro-4-(trimethylsilyloxy)pent-3-en-2-one
作者:Silke Erfle、Sebastian Reimann、Alina Bunescu、Zharylkasyn A. Abilov、Anke Spannenberg、Peter Langer
DOI:10.1002/hlca.201100494
日期:2012.6
cyclocondensation of various 1,3‐bis(trimethylsilyloxy)buta‐1,3‐dienes with 1‐chloro‐1,1‐difluoro‐4‐(trimethylsilyloxy)pent‐3‐en‐2‐one provides a regioselective access to novel 6‐(chlorodifluoromethyl)salicylates (=6‐(chlorodifluoromethyl)‐2‐hydroxybenzoates) with very good regioselectivity. For selected products, it was demonstrated that the CF2Cl group can be transformed to CF2H and CF2(Allyl) by free‐radical