- An unexpected thermal-ring-rearrangement of benzochromenes to inden-3-yl-naphthols with: P TsOH
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Described here is the first report of an unexpected thermal-ring rearrangement (TRR) of benzochromenes to indene derivatives promoted by pTsOH. This cascade ring-rearrangement proceeds through the protonation of benzochromenes by an acid catalyst followed by ring-opening and ring-closure by an intramolecular Friedel-Crafts cyclization to provide a new bicyclic framework, inden-3-yl-naphthols bearing a quaternary center, which also exhibited atropisomerism. Regioselectivity, broad substrate scope, high yields, solvent-free conditions and atom economy are the additional high points of this ring-rearrangement.
- Yaragorla, Srinivasarao,Khan, Tabassum
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supporting information
p. 7920 - 7925
(2018/11/21)
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- Simple, convenient, and efficient synthesis of 2-aryl-substituted benzo[b]furans
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A simple, convenient, and efficient one-pot method for the preparation of benzofuran is reported. Sonogashira coupling reaction of aryl iodides with 2-methyl-3-butyn-2-ol was used as an acetylene source in the presence of Pd(PPh3)2Cl2 and CuI. Deprotection of the acetylene moiety in the same pot using a strong base and the second Sonogashira coupling/cyclization of and substituted o-iodophenols led to the formation of the appropriate benzo[b]furans. These protocols also can be used in the synthesis of natural products and indoles. Copyright Taylor & Francis Group, LLC.
- Jiang, Yong,Gao, Botao,Huang, Wenjuan,Liang, Yongmin,Huang, Guosheng,Ma, Yongxiang
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experimental part
p. 197 - 204
(2009/04/07)
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- High birefringence nematic liquid crystals for display and telecom applications
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Several compounds with high birefringence and, having tolane structure were synthesized. For a high polarizability, isothiocyanato (NCS) terminal group was introduced. Another goal of this study was reduction of melting point and smectic phases by introduction of fluorine as lateral substituent. The transition temperatures for all the synthesized compounds and the refractive and dielectric indices for one of the compounds have been determined. Electro-optic (EO) measurements were also performed.
- Catanescu, Carmen Otilia,Chien,Wu, Shin-Tson
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p. 93/[1135]-102/[1144]
(2007/10/03)
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