Progress towards the synthesis of papuaforin A: selective formation of α-bromoenones from silyl enol ethers
نویسندگان
چکیده
منابع مشابه
Iridium-catalyzed enantioselective allylation of silyl enol ethers derived from ketones and α,β-unsaturated ketones.
The unified Ir-catalyzed enantioselective allylic substitution reactions of silyl enol ethers derived from ketones and α,β-unsaturated ketones with branched, racemic allylic alcohols are described. This transformation is catalyzed by the Carreira system and proceeds without fluoride, and with high ee and b : l ratio. The synthetic utility of this method was illustrated by the concise enantiosel...
متن کاملOne-pot synthesis of tropinone by tandem (domino) ene-type reactions of acetone silyl enol ethers.
A synthetic approach for tropane alkaloids on the basis of tandem (domino) ene-type reactions of acetone silyl enol ethers with iminium ions is shown to be triggered by intermolecular ene-type reactions followed by 6-(2,5) silatropic ene-type cyclizations.
متن کاملFormal (3+3) cycloaddition of silyl enol ethers catalyzed by trifric imide: domino Michael addition-claisen condensation accompanied with isomerization of silyl enol ethers.
We describe here a Tf₂NH-catalyzed formal (3+3) cycloaddition of silyl enol ethers with acrylates as a new domino reaction. In the domino sequence, the catalyst activates Michael addition, deprotonation of the resulting silyloxonium cation and intramolecular Claisen condensation. It was found that reaction modes significantly depend on the reaction temperature. We also examined the mechanistic ...
متن کاملChemo-, regio- and stereoselective preparation of silyl enol ethers from thiol esters and bis(iodozincio)alkane.
Treatment of thiol ester with bis(iodozincio)alkane in the presence of palladium catalyst followed by silylation affords Z-silyl enol ether chemo-, regio- and stereoselectively.
متن کاملSynthesis of cyclopentenones from cyclopropanes and silyl ynol ethers.
Five-membered carbocyclic rings appear in all classes of organic materials including pharmaceutical agents, polymers, natural products, and catalysts. Accordingly, their preparation has challenged synthetic chemists since the inception of the field. In this regard, [3+2] cycloadditions—both concerted and stepwise—represent convergent strategies for the formation of the cyclopentane nucleus. Dip...
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ژورنال
عنوان ژورنال: Tetrahedron Letters
سال: 2008
ISSN: 0040-4039
DOI: 10.1016/j.tetlet.2007.11.069