6053-74-3Relevant articles and documents
An experimental thermochemical and theoretical study of triquinacene: Definitive disproof of its neutral homoaromaticity
Verevkin, Sergey P.,Beckhaus, Hans-Dieter,Rüchardt, Christoph,Haag, Rainer,Kozhushkov, Sergei I.,Zywietz, Tosja,De Meijere, Armin,Jiao, Haijun,Von Ragué Schleyer, Paul
, p. 11130 - 11135 (1998)
The enthalpy of formation (ΔH(f)/°(g) = 57.51 ± 0.70 kcal/mol) of triquinacene (1), newly determined by measuring its energy of combustion in a microcalorimeter, is about 4 kcal/mol higher than that previously reported and corresponds to ab initio and density functional theory computational results. As a consequence, the previously derived homoaromatic stabilization energy (claimed to be 4.5 kcal/mol) from enthalpy of hydrogenation measurements is not present in 1. The lack of homoaromaticity in 1 is supported by evaluation of geometric, energetic, and magnetic criteria. In contrast, the isomerization transition state from diademane (5) to 1 is highly aromatic on the basis of the same criteria. The enthalpy of isomerization of 5 to 1 was experimentally determined by differential scanning calorimetry (DSC) to be -29.4 ± 0.3 kcal/mol (measured at 368.2 K). The enthalpy of activation for this rearrangement as determined from the DSC measurements (28.4 ± 0.2 kcal/mol) is 2.5 kcal/mol higher than the value computed at B3LYP/6311+G**+ZPE.
THE SYNTHESIS OF TRIQUINACENE VIA THE WEISS REACTION.
Bertz, Steven H.,Lannoye, G.,Cook, J. M.
, p. 4695 - 4698 (1985)
A short, simple preparation of triquinacene 1 is based on four key steps: the Weiss reaction, high-yield monoalkylation of the resulting bicyclo system, aldol cyclization of aldehyde 6 and HMPA-mediated dehydration of triol 8.
LiCB11Me12: A catalyst for pericyclic rearrangements
Moss, Stefan,King, Benjamin T.,De Meijere, Armin,Kozhushkov, Sergei I.,Eaton, Philip E.,Michl, Josef
, p. 2375 - 2377 (2007/10/03)
(matrix presented) Benzene and 1,2-dichloroethane solutions of the Li+ salt of the weakly coordinating anion CB11Me12- catalyze the rearrangement of cubane to cuneane, quadricyclane to norbornadiene, basketene to Nenitzescu's hydrocarbon, and diademane to triquinacene. The Claisen rearrangement of phenyl allyl ether is also strongly accelerated.
General Approach to the Synthesis of Poliquinenes. 8. Synthesis of Triquinacene, 1,10-Dimethyltriquinacene, and 1,10-Cyclohexanotriquinacene
Gupta, Ashok K.,Lannoye, Greg S.,Kubiak, Greg,Schkeryantz, Jeff,Wehrli, Suzanne,Cook, James M.
, p. 2169 - 2179 (2007/10/02)
The synthesis of tricyclo4,10>deca-2,5,8-triene (1), 1,10-dimethyltricyclo4,10>deca-2,5,8-triene (3), and tetracyclo1,8.04,8>tetradeca-2,5,13-triene (4) has been accomplished via the reaction of 1,2-dicarbonyl compounds with di-tert-butyl 3-oxoglutarate (Weiss reaction).Condensation of glyoxal 5a with di-tert-butyl 3-oxoglutarate (6b) gave the tetra-tert-butyl cis-dioxobicyclooctane-2,4,6,8-tetracarboxylate 7b in 93percent yield.This bisenol 7b was converted into the bisenol ether 9b regiospecifically (90percent yield).This transformation was followed by monoalkylation (KH, allyl iodide; -58 deg C) and hydrolysis to generate 2-allyl-cis-bicyclooctane-3,7-dione in 90percent overall yield from 9b.The mixture of epimiric 2-allyl-3,7-diones 11a,b was transformed (O3; DMS) into the mixture of epimiric aldehydes 12a,b.This process was followed by aldol cyclization (2 N HCl, THF) to provide the diastereomeric mixture of of endo-(13a) and exo-(13b) triquinane monols in 85percent yield.Reduction of 13a,b with borane-THF (0 deg C) generated the stereoisomeric mixture of triols 14a,b which were subjected to an HPMA-mediated dehydration sequence to provide triquinacene (1), accompanied by small amounts of isotriquinacene.The mixture of trienes were converted into pure 1 by exposure to p-TSA in methylene chloride-pentane.Substitution of biacetyl (5b) for glyoxal 5a in the Weiss reaction, followed by the analogous steps detailed in the synthesis of 1, provided 1,10-dimethyltriquinacene (3).In addition, the synthesis of 1,10-cyclohexanotriquinacene (4), another centro-substituted triquinacene, has been accomplished by substitution of cyclohexane-1,2-dione (23) for 5a in the condensation, followed by the same sequence of reactions presented above for 1 and 3.
