13255-85-1Relevant articles and documents
Photocyclization of cinnamylnaphthols
Jimenez, M. Consuelo,Leal, Pablo,Miranda, Miguel A.,Scaiano, Juan C.,Tormos, Rosa
, p. 4337 - 4344 (1998)
The naphtholic chromophore is responsible for the photophysical and photochemical properties of cinnamylnaphthols le, f. Both fluorescence emission and photocyclization occur from the naphtholic singlet excited slates. The formation of five- and six- membered ring products (2e and 3e, f) is shown to involve a proton transfer mechanism. The low efficiency of trans to cis isomerization is explained as the result of deactivation of the styrenic triplet via intramolecular energy transfer. The resulting naphtholic triplets behave as energy sinks.
4,5-Dimethyl-2-Iodoxybenzenesulfonic Acid Catalyzed Site-Selective Oxidation of 2-Substituted Phenols to 1,2-Quinols
Uyanik, Muhammet,Mutsuga, Tatsuya,Ishihara, Kazuaki
, p. 3956 - 3960 (2017/03/27)
A site-selective hydroxylative dearomatization of 2-substituted phenols to either 1,2-benzoquinols or their cyclodimers, catalyzed by 4,5-dimethyl-2-iodoxybenzenesulfonic acid with Oxone, has been developed. Natural products such as biscarvacrol and lacinilene C methyl ether could be synthesized efficiently under mild reaction conditions. Furthermore, both the reaction rate and site selectivity could be further improved by the introduction of a trialkylsilylmethyl substituent at the 2-position of phenols. The corresponding 1,2-quinols could be transformed into various useful structural motifs by [4+2] cycloaddition cascade reactions.
Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
, p. 5221 - 5233 (2014/07/08)
Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2 while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation- esterification process at 120-130°C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2- ones were obtained in 5-85% yields.
Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
, p. 5221 - 5233 (2014/12/10)
Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation-esterification process at 120-130 °C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2-ones were obtained in 5-85% yields.
Trapping of active methylene intermediates with alkenes, indoles or thiols: Towards highly selective multicomponent reactions
Gu, Yanlong,Barrault, Joel,Jerome, Francois
supporting information; experimental part, p. 3269 - 3278 (2010/04/24)
In this paper, a basic method to access new multicomponent reactions (MCRs) is reported. The mechanism of these MCRs is based on the trapping of methylene intermediates, formed in situ by reaction of formaldehyde with electron-rich carbons, with alkene, thiol or indole derivatives. According to our strategy, a wide range of valuable skeletons has been obtained in a one-pot reaction, thus allowing a minimization of waste, cost and labor. The presented methodology exhibits a broad substrate scope and electron-rich carbons in the α-position of a hydroxy or carbonyl group were found to be particularly efficient. More generally, this work offers new tools for creating molecular complexity and diversity from one of the simplest organic building blocks, formaldehyde.
Synthesis of chromans from the reaction of o-quinone methide precursor with substituted styrenes
Bilgic, Sevim,Bilgic, Orhan,Bueyuekkidan, Buelent,Guenduez, Murat
, p. 76 - 79 (2008/02/02)
In this work, the inverse-electron demanded Diels-Alder cycloaddition reaction of 1-dimethylaminomethyl-2-naphthol and 2-dimethylaminomethyl-4,5- dimethylphenol with (un)substituted styrenes were investigated. 3,4-Dihydro 2-(un)substitutedphenyl-2H-benzo[
