22360-62-9Relevant academic research and scientific papers
The intramolecular reaction of acetophenoneN-tosylhydrazone and vinyl: Br?nsted acid-promoted cationic cyclization toward polysubstituted indenes
Wang, Zhixin,Li, Yang,Chen, Fan,Qian, Peng-Cheng,Cheng, Jiang
, p. 1810 - 1813 (2021/02/27)
In the presence of TsNHNH2, a Br?nsted acid-promoted intramolecular cyclization ofo-(1-arylvinyl) acetophenone derivatives was developed, leading to polysubstituted indenes with complexity and diversity in moderate to excellent yields. In sharp contrast with either the radical or carbene involved cyclization of aldehydicN-tosylhydrazone with vinyl, a cationic cyclization pathway was involved, whereN-tosylhydrazone served as an electrophile and alkylation reagent during this transformation.
Structure-reactivity relationships in (2-hydroxyethyl)benzophenone photoremovable protecting Groups
Pirrung, Michael C.,Roy, Biswajit Gopal,Gadamsetty, Surendra
supporting information; experimental part, p. 3147 - 3151 (2010/05/18)
A detailed study of substituent effects on the photochemical conversion of esters of (2-hydroxyethyl)benzophenone to the carboxylic acid was performed with the aim of improving on the reactivity of the parent, which was first reported decades ago. Over 20
Synthesis and structure of 2-aryl-2,4-dimethyl-1,2,3,4-tetrahydroquinolines and 1,3-disubstituted indenes
Zvolinskii,Kryvenko,Sergeeva,Soldatenkov,Prostakov
, p. 86 - 90 (2007/10/03)
It has been shown that the intramolecular cyclization of N-(1-arylbutenyl)arylamines under acid catalysis conditions may proceed in two directions with the formation of 2-aryl-2,4-dimethyl-1,2,3,4-tetrahydroquinolines and 1,3 disubstituted indenes. 1997 P
Friedel-Crafts-type reactions involving di- and tricationic species. Onium-allyl dications and O,O-diprotonated aci-nitro species bearing a protonated carbonyl group
Ohwada, Tomohiko,Yamagata, Naoko,Shudo, Koichi
, p. 1364 - 1373 (2007/10/02)
Stable carbocations do not react with nonactivated benzenes. For example, acetophenone does not react with benzene in the presence of trifluoromethanesulfonic acid (TFSA), while trifluoroacetophenone does do so under acidic conditions owing to activation of the electrophilicity of the hydroxycarbenium cation by the trifluoromethyl group. This and other studies suggest that an electron-withdrawing substituent on the cationic center increases the reactivity toward benzenes. In this paper, involvement of multiply positively charged (dicationic and tricationic) species, which have sufficient electrophilicity toward benzene, is demonstrated in the acid-catalyzed reactions of cinnamaldehyde and its derivatives and also in the acid-catalyzed reactions of nitromethanes. The species formed from cinnamaldehyde, cinnamaldimine, cinnamaldoxime, and their derivatives in TFSA or TFSA-SbF5 have an adequate reactivity toward benzene. O-Protonated cinnamaldehyde and its derivatives, N-protonated cinnamaldimine, and N,N-dimethylcinnamaldiminium salt do not react with benzene. Since a strong acid catalyst is required for the reactions, participation of doubly protonated species, onium-allyl dications, is proposed. Ab initio calculations of (1) the donor-acceptor interaction energies of a neutral donor (such as water and ammonia) and a doubly charged allyl dication and (2) proton affinities demonstrated that the ammonium-allyl dication is more stable than the oxonium-allyl dication, in accordance with the experimental observation. Nitronic acids also react with benzene at the ipso position with respect to the nitro group to give the phenylated oximes in the presence of TFSA. The reaction with benzene is not catalyzed by trifluoroacetic acid, which is sufficiently acidic to monoprotonate a nitronic acid to the protonated aci-nitro form. The reaction requires a stronger acid, trifluoromethanesulfonic acid, suggesting intervention of the dication formed by O,O-diprotonation of acinitroalkanes rather than the monoprotonated aci-nitroalkane. As a result of further study on the phenylation reactions, we found a facile phenylation reaction of nitromethanes substituted with an electron-withdrawing group, catalyzed by TFSA, to give phenylated α-carbonyloximes in high yields. A triply positively charged cation, an O,O-diprotonated aci-nitro species bearing a protonated ethoxycarbonyl group, which can react with nonactivated benzene, is proposed to be an intermediate in this reaction.
Dissolving Metal Reduction of Aceanthrylene and NMR Analysis of a Rigid, Boat-Shaped 9,10-Dihydroanthracene
Rabideau, Peter W.,Mooney, Jennifer L.,Smith, W. Kimmer,Sygula, Andrzej,Paschal, Jonathan W.
, p. 589 - 591 (2007/10/02)
Aceanthrylene is reduced by sodium/ammonia solution to its 2,6-dihydro derivative (4), which indicates a protonation site in the dianion in contrast to the MNDO-calculated position of highest electron density.It is concluded that monoanion stability must be the prevailing feature.Compound 4 is also reduced by sodium/ammonia to provide 1,9-ethano-9,10-dihydroanthracene, which allowed the first proton NMR study of a rigid, boat-shaped dihydroanthracene.Especially interesting are the long range, five-bond homoallylic couplings between the 9- and 10-positions, and the values measured are 4.7 Hz for 5J9,10 (dipseudoaxial) and 1.4 Hz for 5J9,10' (pseudoaxial/pseudoequatorial).The protonation and alkylation of (3-phenylindenyl)lithium is also considered so as to better understand the behavior of the intermediates derived from aceanthrylene.
Ozonolysis of a Series of 1-Substituted Indenes. The Substituent Steric Effects on Ozonide Exo/Endo Ratios
Miura, Masahiro,Nojima, Masatomo,Kusabayashi, Shigekazu,McCullough, Kevin J.
, p. 2932 - 2936 (2007/10/02)
The ozonolysis of a series of disubstituted (1,2 and 1,3) and trisubstituted (1,2,3) indenes 1-28 in carbon tetrachloride at 20 deg C has been investigated.The major product in each case was the corresponding bicyclic ozonide, usually obtained as a mixtur
