Novel dialkyloxy- and dihydroxyoctahydroperylenes are regioselectively available via a new tandem Friedel-Crafts alkylation of tetrahydronaphthalene precursors followed by oxidative aromatization. Heating of 5-alkyloxy-1-tetralol with p-toluenesulfonic acid in sulfolane gave the corresponding octahydroperylenes in moderate yields. Studies with Lewis acids and tetralin-1,5-diol in acetonitrile at room temperature provided the 4,10-dihydroxy analogue cleanly, albeit in reduced yields. Examples of these new series of perylene analogues were partially oxidized to the corresponding contiguously aromatic, anthracene core products or fully aromatized to 3,9-dialkyloxyperylenes in good yields.
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http://dx.doi.org/10.1021/jo800558c | DOI Listing |
J Am Chem Soc
December 2024
Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven, Celestijnenlaan 200F, Post box 2454, 3001 Leuven, Belgium.
Due to the high demand and the increasing production rate of plastic materials, vast amounts of wastes are generated every year. An important fraction of these wastes contain polystyrene (PS), which is seldom recycled, neither mechanically nor chemically. While several chemical recycling strategies have been developed, they are either very energy-demanding or produce chemicals that can hardly be employed in the synthesis of plastics (e.
View Article and Find Full Text PDFChem Commun (Camb)
October 2024
Departament de Química Orgànica, Facultat de Química, Universitat de València, Dr Moliner 50, 46100 Burjassot, València, Spain.
The catalytic asymmetric electrophilic functionalization of the less reactive N-heteroaromatic compounds has been reported using the approach of the introduction of an exocyclic amino substituent. This strategy has allowed enantioselective Friedel-Crafts alkylation in pyrazoles, isoxazoles and isothiazoles, as well as in aminoindoles, aminobenzofurans and aminobenzothiophenes. Several stereoselective methods have been used for the 1,4-addition or 1,2-addition of these heteroaromatic compounds to different electrophiles employing organocatalysts or chiral metal complexes.
View Article and Find Full Text PDFJ Org Chem
August 2024
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India.
A novel and efficient tandem protocol for the swift synthesis of dihydrobenzo[]indenocarbazole frameworks from 2-alkynylanilines and 2-alkynylbenzaldehydes via BF·OEt-facilitated benzannulation and Friedel-Crafts reaction has been described. This innovative approach accommodates a wide array of functional groups, offering a myriad of diversified carbazole products. Later, postsynthetic modification leads to its C(sp)-H hydroxylation.
View Article and Find Full Text PDFOrg Lett
June 2024
Key Laboratory of Syngas Conversion of Shaanxi Province, Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, P.R. China.
The efficient construction of π-conjugated polycyclic heteroarenes represents a significant task in the field of functional materials. A one-step oxidative tandem cyclization of aromatic acids with (benzo)thiophenes was developed to access planar sulfur-containing polycyclic heteroarenes. This protocol undergoes intermolecular cross-dehydrogenative coupling followed by intramolecular Friedel-Crafts acylation and provides a facile pathway to planar polycyclic compounds from inexpensive reactants.
View Article and Find Full Text PDFOrg Lett
June 2024
College of Sciences and College of Forestry, Henan Agricultural University, Zhengzhou 450002, China.
Described herein is an efficient copper-catalyzed tandem alkyne indolylcupration-initiated 1,2-indole migration/6π-electrocyclic reaction of allene-ynamides with indoles by the in situ-generated metal carbenes. This method allows the efficient synthesis of valuable indole-fused spirobenzo[]indole-cyclohexanes with high regio- and stereoselectivity. In addition, this reaction affords rapid access to the functionalized spirobenzo[]indole-cyclohexanes in the absence of indoles by a presumable 5-exo-dig cyclization/Friedel-Crafts alkylation via copper-containing all-carbon 1,4-dipoles.
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