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Journal ArticleDOI

Mercury(II) trifluoroacetate-mediated cyclisation of aryl allenic ethers

04 Nov 1991-Tetrahedron Letters (Pergamon)-Vol. 32, Iss: 45, pp 6641-6644
Abstract: Mercury(II) trifluoroacetate brings about a facile cyclisation of aryl allenic(aryl 2,3-butadien-1-yl) ethers to 4-methyl-2H-1-benzopyrans and 4-methylene-3,4-dihydro-2H-1-benzopyrans in excellent yield.
Topics: Aryl (56%), Mercury (element) (53%)
Citations
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Journal ArticleDOI
TL;DR: The electrophilic cyclization of substituted propargylic aryl ethers by I2, ICl, and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields.
Abstract: The electrophilic cyclization of substituted propargylic aryl ethers by I2, ICl, and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields. This methodology results in vinylic halides or selenides under mild reaction conditions and tolerates a variety of functional groups, including methoxy, alcohol, aldehyde, and nitro groups.

133 citations


Journal ArticleDOI
09 Oct 2007-Organic Letters
TL;DR: Gold-catalyzed intramolecular hydroarylation of allenic anilines and phenols offers an efficient route to dihydroquinoline and chromene derivatives under mild reaction conditions, leading to a highly selective formation of six-membered rings.
Abstract: Gold-catalyzed intramolecular hydroarylation of allenic anilines and phenols offers an efficient route to dihydroquinoline and chromene derivatives under mild reaction conditions. The hydroarylation takes place at the terminal or central allenic carbon depending on the substrate structure, leading to a highly selective formation of six-membered rings.

107 citations


Journal ArticleDOI
Abstract: A variety of mono- and disubstituted phenols are alkylated with propargyl bromide to give phenyl 2-propynyl ethers, which were further coupled with aryl iodides under Sonogashira reaction conditions to give 3-phenoxy-1-aryl-1-propyne derivatives. The latter compounds underwent an initial Claisen rearrangement followed by ring closure to give functionalized benzo[ b ]furans in moderate to good yields.

34 citations


Journal ArticleDOI
Abstract: Treatment of N-alkyl-N-allenylmethylanilines with magnesium monoperoxyphthalate in methanol–water underwent tandem transformations to furnish N-alkyl-2-ethenylindoles in good yield.

16 citations


Journal ArticleDOI
Abstract: A stereocontrolled synthetic approach to E - and Z -substituted methylene-3,4-dihydro-2 H -1-benzopyrans 5 is described from acyclic derivatives using as a key step the palladium-catalyzed intramolecular cyclic carbopalladation of iodoalkynes 4 followed by a carbonylation or a hydride ion capture process.

12 citations


References
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Journal ArticleDOI
Abstract: Le (bis-[(bromo-4 di-t-butyl-2,6)phenoxy methyl) aluminium peut etre utilise pour obtenir l'isomere (Z) alors que l'isomere (E) est produit avec le (bis-[diphenyl-2,6 phenoxy] methyl) aluminium

112 citations



Journal ArticleDOI
Abstract: Les cyclisations sont obtenues par reaction avec la piperidine ou la triethylamine en presence d'un catalyseur au palladium: obtention d'heterocycles azotes ou oxygenes a 5, 6 ou 7 chainons

64 citations


Journal ArticleDOI
TL;DR: This is the first to show that meta-Claisen rearrangement occurs preferentially even when a free para position is available, and can be interpreted in terms of the small bond energy of the breaking apical carbon-iodine (III) bond.
Abstract: Reported for the first time are the generation of allenyliodinanes and their reductive iodonio-Claisen rearrangement Reaction of propargylsilanes, germanes, and stannanes with aryliodinanes in the presence of BF 3 -Et 2 O undergoes a reductive iodonio-Claisen rearrangement under mild conditions, yielding o-propargyliodoarenes in good yields The reductive ortho propargylation probably involves the intermediate formation of allenyl(aryl) iodinanes, which undergo [3,3]-sigmatropic rearrangement The lack of crossover products argues for the intramolecularity of the rearrangement When both ortho positions of aryliodinanes are occupied with alkyl substituents, the reductive iodonio-Claisen rearrangement affords meta substitution products This is the first to show that meta-Claisen rearrangement occurs preferentially even when a free para position is available The reductive ortho propargylation of iodinanes takes place under much milder conditions than the Claisen rearrangement The lower activation energy associated with the iodonio-Claisen rearrangement of allenyl(aryl) iodinanes can be interpreted in terms of the small bond energy of the breaking apical carbon-iodine (III) bond

60 citations