scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Thermal Claisen rearrangement of aryl allenylmethyl ethers: synthesis of 2-(o-hydroxyaryl)buta-1,3-dienes and 4-methyl-2H-1-benzopyrans

01 Jan 1992-Journal of The Chemical Society, Chemical Communications (The Royal Society of Chemistry)-Iss: 24, pp 1760-1761
TL;DR: In this paper, aryl allenylmethyl ethers in diethylene glycol were rearranged to yield 2-(o-hydroxyaryl)buta-1,3-dienes and 4-methyl-2H-1-benzopyrans.
Abstract: Thermal Claisen rearrangement of aryl allenylmethyl ethers in diethylene glycol afforded 2-(o-hydroxyaryl)buta-1,3-dienes and 4-methyl-2H-1-benzopyrans in good yield.
Citations
More filters
Journal ArticleDOI
TL;DR: A new intramolecular para cycloaddition of arenes with allenes, yielding attractive rigid scaffolds bearing several reactive functionalities to build in further diversity, and was scaled up to multigram quantities without erosion of the typically high yields in photocycloadducts.
Abstract: In this work, we report on a new intramolecular para cycloaddition of arenes with allenes, yielding attractive rigid scaffolds bearing several reactive functionalities to build in further diversity. Bicyclo[2.2.2]octadiene-type products and benzoxepine acetals are formed in this reaction, in ratios and yields depending on the substitution pattern on the aromatic ring, the nature of the chromophore, and the tether. This unprecedented reaction has remarkable features that distinguish it from many other photochemical transformations: it is particularly robust with respect to substituents, it can be scaled up without a notable loss of efficiency, and it can lead to structures with a high degree of complexity in low to good yields. All photochemical precursors could be synthesized readily in three steps. We confirmed the compatibility of the nitrogen atom in the photocycloaddition step, which gives access to a bicyclo[2.2.2]octadiene scaffold with two points that allow further diversification. This reaction wa...

24 citations

Journal ArticleDOI
TL;DR: An FeCl3-catalyzed allenic Claisen rearrangement/regio- and chemoselective aerobic dehydrogenative cyclization domino reaction is developed, providing a wide range of 2-aryl/alkyl, 3-(substituted-vinyl)naphtho[2,1- b]furans in high yields at 95-130 °C in an atom- and step-economic fashion.

16 citations

Journal ArticleDOI
TL;DR: In this article, a review of reaction chemistry and new ring synthetic methods for pyranones is presented, which covers work published in the calendar year 2010 and includes new ring synthesis methods for trioxanes, tetraoxane, dioxanes, trithianes and oxathianes.
Abstract: The review covers work published in the calendar year 2010. Novel reaction chemistry and new ring synthetic methods for pyrans, [1]benzopyrans, dihydro[1]benzopyrans (chromenes, chromans), [2]benzopyrans, dihydro[2]benzopyrans (isochromenes, isochromans), pyranones, coumarins, chromones, xanthenes, xanthones, thiopyrans, dioxins. dioxanes, trioxanes, tetraoxanes, dithianes, trithianes, oxathianes are reviewed.

10 citations

Journal ArticleDOI
TL;DR: Simple and mild methods for the synthesis of allenes, employing indium- and zinc-mediated dehalogenation reactions of vicinal dihalides in an aqueous solvent, are described.
Abstract: Simple and mild methods for the synthesis of allenes, employing indium- and zinc-mediated dehalogenation reactions of vicinal dihalides in an aqueous solvent, are described. By using these procedures, various allenylmethyl aryl ethers and monosubstituted allenes have been prepared in good to excellent yields.

10 citations

References
More filters
Journal ArticleDOI
TL;DR: A number of allyl allenyl ethers (1) have been synthesised and shown to undergo the Claisen rearrangement as discussed by the authors, which is consistent with a concerted mechanism for these rearrangements.

21 citations

Journal ArticleDOI
TL;DR: Mercury(II) trifluoroacetate brings about a facile cyclisation of aryl allenic(aryl 2,3-butadien-1yl) ethers to 4-methyl-2H-1-benzopyrans.

17 citations

Journal ArticleDOI
TL;DR: In this article, the regioselectivity of cycloaddition reactions of trichloronitrosomethane with 2-alkyl and 2-aryl was investigated.
Abstract: The regioselectivity of cycloaddition reactions of trichloronitrosomethane (1) with 2-alkyl (R = Me, Et, i-Pr, t-Bu, CF3, Bz, and Cl) and 2-aryl (Ar = Ph, 4-CH3OPh, 4-CH3Ph, 3-CH3Ph, and 4-ClPh) 1,...

7 citations