1521-59-1Relevant articles and documents
A Hexavalent Basket for Bottom-Up Construction of Functional Soft Materials and Polyvalent Drugs through a “Click” Reaction
Neal, Taylor A.,Wang, Weikun,Zhiquan, Lei,Peng, Ruojing,Soni, Priti,Xie, Han,Badji?, Jovica D.
, p. 1242 - 1248 (2019)
Inspired by polyvalency and its prevalence in nature, we developed an efficient synthetic route for accessing a large variety of multivalent and dual-cavity baskets from inexpensive and abundant starting materials. First, the cycloaddition of vinyl acetate to anthracene was optimized to, upon hydrolysis, give dibenzobarrelene derivative 6, which after five functional group transformations and then cyclotrimerization gave heptiptycene dodecaester 4 in an overall 17 % yield. Following that, compound 4 was converted into D3h symmetric 1, composed of two fused cavitands each holding three terminal alkynes at the rim for conjugation to functional molecules using the highly efficient CuAAC reaction. To survey the reactivity of hexavalent 1, we “clicked” 2-acetamido-2-deoxy-β-d-glucopyranosyl azide 3,4,6-triacetate (carbohydrate), methoxypolyethylene glycol azide (PEG, Mn=2000; polymer) and benzyl azide (aromatic) to obtain hexavalent conjugates 12–14 in 50–79 % yields. In summary, dual-cavity 1 is an accessible, structurally-unique and hexavalent host that can be “clicked” to a variety of functional molecules for (a) combinatorial lead identification of drugs, (b) preparation of hierarchical soft materials and (c) design of selective chemosensors, scavengers, or supramolecular catalysts.
Structure study of dibenzobicyclooctane alcohols
Stǎnescu, Michaela Dina,Florea, Cristina,Chiraleu, Filip,H?rtopeanu, Anca,Sezonov, Paul
, p. 861 - 866 (2007/10/03)
Alcohols with a dibenzobicyclooctane skeleton have been synthesized and their 1H- and 13C-NMR spectra performed. The structure of the three isomers has been discussed on the basis of their spectral data. The results are in agreement with the calculated molecular geometries.
Distortion of Olefin and Carbonyl ?-Orbitals in Dibenzobicyclooctatrienes and Dibenzobicyclooctadienones. Unsymmetrization of ? Lobes Arising from ?-? Orbital Interactions
Ohwada, Tomohiko,Okamoto, Iwao,Haga, Naoki,Shudo, Koichi
, p. 3975 - 3984 (2007/10/02)
We have detected the unsymmetrical ? faces of the olefin group in 2-substituted dibenzobicyclooctatrienes (2-substituted 9,10-dihydro-9,10-ethenoanthracenes) and the carbonyl groups of 2-substituted and 3-substituted dibenzobicyclooctadienones (2-substituted and 3-substituted 9,10-dihydro-9,10-(11-ketoethano)anthracenes), wherein ?-type overlaps of the ? orbitals are involved, in a similar manner to longicyclic conjugation.An intrinsically nonequivalent substituent at distal positions modulates the epoxidation and dihydroxylation of the olefin group and the reduction of the carbonyl group.Both systems exhibit similar substituent effects: an "electron-withdrawing" substituent such as a nitro or fluoro group gave a large to moderate bias (preferred syn attack with respect to the substituent) whereas an "electron-donating" methoxy substituent exhibited a negligible bias.Herein we interpret these biases or nonbiases in terms of unsymmetrization of ? lobes of the olefin and carbonyl ? orbitals, arising from nonequivalent ?-? interactions rather than from an electron-donating or -withdrawing effect.
COMPETITIVE REARRANGEMENTS. I. NEOPENTYLIC VERSUS SKELETAL BICYCLOOCTANE -> BICYCLOOCTANE REARRANGEMENTS
Ionica, Ileana,Ghiviriga, Ion,Filip, Petru,Badea, Florin,Dinulescu, Ilie G.
, p. 1007 - 1016 (2007/10/03)
Generation of a carbenium ion common to two systems which are able to undergo either a skeletal bicyclooctane --> bicyclooctane rearrangement or a neopentylic rearrangement conducts only to the latter reaction. Thus, 8-carbomethoxy-7-t-butyl-dibenzobicyclooctatriene (15) reacts with strong acids or bromine, yielding neopentyl rearranged products 17, respectively 21. Reaction mechanisms are proposed.
DECARBOXYLATIVE PHOTOOXYGENATION OF CARBOXYLIC ACIDS BY THE USE OF ACRIDINE
Okada, Keiji,Okubo, Katsura,Oda, Masaji
, p. 83 - 84 (2007/10/02)
A new method of decarboxylative photooxygenation of free carboxylic acids is developed by the use of acridine as a light absorber, leading to alcohols after reductive treatment of the photolysate.
Chemistry of Bridged Aromatics. A Study of the Substituent Effect on the Course of Bond Cleavage of 9,10-Dihydro-9,10-ethanoanthracenes and an Oxyanion-Assisted Retro-Diels-Alder Reaction
RajanBabu, T. V.,Eaton, David F.,Fukunaga, Tadamichi
, p. 652 - 657 (2007/10/02)
The retro-Diels-Alder reactions of 9,10-dihydro- and 1,4,9,10-tetrahydro-9,10-ethanoanthracenes are dramatically accelerated by an oxyanion substitution on the 2? component, i.e., the ethano bridge.Studies of related systems bearing anionic, cationic, and radical substituents indicate that the cycloreversion is concerted and occurs only if both 4? and 2? fragments are highly resonance stabilized.