17407-24-8Relevant academic research and scientific papers
Acid-catalyzed cyclization of anthracenol derivatives to homotriptycenes
Gao, Chunmei,Cao, Derong,Xu, Sheyang,Meier, Herbert
, p. 3071 - 3076 (2007/10/03)
10-Benzyl-9,10-dihydroanthracen-9-ols, having high electron densities in the benzene ring, exhibit in the presence of acid a transannular ring closure to the corresponding homotriptycenes in almost quantitative yields. Since the starting compounds are easily accessible from 9(10H)-anthracenone, this process represents the most facile route to such pentacyclic systems. An electron-releasing methoxy group enables the intramolecular electrophilic substitution in its para position. In the absence of such an activation, a number of alternative processes can occur, namely the acid-catalyzed dehydration to anthracene derivatives with (R ≠ H) or without (R = H) rearrangement or a disproportionation reaction of the secondary alcohol to the corresponding ketone and hydrocarbon.
A facile synthesis of homotriptycenes from anthranol derivatives
Cao, Derong,Gao, Chunmei,Meier, Herbert
, p. 3166 - 3168 (2007/10/03)
Substituted trans-10-benzyl-9-anthranols 5a,b and substituted 10, 10-dibenzyl-9-anthranol 8e undergo intramolecular cyclization in the presence of formic or oxalic acid to give homotriptycenes 9a,b,e. Depending on the amount of acid used, a competitive 1,
Protonation and Alkylation of Ambident (9-Anthryl)arylmethyl Anions
Takagi, Masato,NOjima, Masamoto,Kusabayashi, Shigekazu
, p. 4676 - 4684 (2007/10/02)
We have investigated the protonation of ambident (9-anthryl)arylmethylsodiums (Na-2) and -lithiums (Li-2) (substituent =p-Me, p-Me, H, m-F) with various oxygen and carbon acids in tetrahydrofuran to give a mixture of the anthracene derivatives 3a-d and the 9,10-dihydroanthracenes 4a-d.Product compositions were dramatically influenced by the substituent electronic effects of the carbanions 2 and the acidities of the proton donors.In the protonation with the oxygen proton donors the change of the countercation 2 and the addition of hexamethylphosphoramide also exerted remarkable effects on the 3:4 ratio, whereas these two factors were not important in the case of the carbon acids.This fact would be interpreted as the extent of coordination of oxygen acids to metal cations being important in determining protonation regiochemistry.The reaction of (9-anthryl)arylmethyl anions (2a-d) with a series of aliphatic and benzylic halides gave a mixture of two cross-coupling products, 7 (coupling at C-α) and 8 (coupling at C-10), and/or dimers, 5 Cα-C10 coupling) and 6 (C10-C10 coupling), the composition being influenced by the substituent electronic effects of the carbanions 2 and structure of the alkyl groups of the halides.The leaving group effects also have a significant influence on the product composition.Using dependence (or independence) of the product composition on the electronic effects of the substituent of 2 as a tool to differentiate the reaction mechanisms, we have attempted to rationalize the apparently complicated alkylation of the carbanions 2.
Reaction of (9-anthryl)arylmethyl Chlorides with Grignard and Lithium Reagents
Takagi, Masato,Nojima, Masatomo,Kusabayashi, Shigekazu
, p. 1636 - 1643 (2007/10/02)
We have investigated the reaction of (9-anthryl)arylmethyl chlorides 1a-d (para substituent = MeO, Me, H, and Cl) with Grignard and lithium reagents.The variables are the structures of the alkyl group of Grignard and lithium reagents (alkyl group = tert-b
Reactions of (9-Anthryl)arylmethyl Chloride and Its Homologues with Nucleophiles under Solvolytic Conditions. Notable Effects of Reaction Conditions and Substituents on the Reaction Sites
Ogata, Fujimaro,Takagi, Masato,Nojima, Masatomo,Kusabayashi, Shigekazu
, p. 1145 - 1153 (2007/10/02)
The reactions of (9-anthryl)arylmethyl chlorides 2a-e (the substituents are p-MeO, p-Me, H, p-Cl, and m-Cl), the corresponding bromides 3b-d (the substituents are p-Me, H, and p-Cl), and the antimonate salts 4b-e (the substituents are p-Me, H, p-Cl, and m
