539-80-0Relevant academic research and scientific papers
The Configuration and Conformation of the Tricyclo2,5>dodecan-11-ols Determined by 1H NMR Spectroscopy using the Shift Reagent Eu(fod)3
Mason, Timothy J.
, p. 321 - 323 (1981)
The isomeric tricyclo2,5>dodecan-11-ols have been synthesized from the (6+4) cycloaddition product of tropone with cyclopentadiene.The configuration and conformation of each isomer was determined from the proton shift gradients induced in the olefinic proton signals in the 1H NMR spectra of intermediate compounds by Eu(fod)3.
A New and Simple Synthesis of Tropones
Banwell, Martin G.
, p. 847 - 848 (1982)
3- and 4-Halogenocycloheptatrienones can be prepared from the Δ2- and Δ3-norcarenes (1), (2), and (3) by an allylic oxidation-dehydrohalogenation sequence; evidence for the intermediacy of the bicyclic enones (4)-(7) in the formation of the troponoid skeleton is presented.
Organocatalytic stereoselective [8+2] and [6+4] cycloadditions
Mose, Rasmus,Preegel, Gert,Larsen, Jesper,Jakobsen, Sofie,Iversen, Eva H?gh,J?rgensen, Karl Anker
, p. 487 - 492 (2017)
Cycloadditions that involve more than six I € electrons are termed higher-order cycloadditions and are an excellent tool for solving complex synthetic challenges, as they provide direct access to polycyclic scaffolds that contain medium-sized rings. They have interesting synthetic potential for the discovery of new bioactive molecules and in natural product synthesis. It is peculiar that stereocontrolled [8+2] and [6+4] cycloadditions have been largely neglected for the past 50 years. Here we demonstrate a cross-dienamine activation of 2-cyclopentenone and the unprecedented endocyclic linear-dienamine activation of 2-cyclohexenones and 2-cycloheptenones. These dienamine intermediates undergo aminocatalytic stereoselective [8+2], [6+4] and formal [4+2] cycloadditions with various heptafulvenes. The periselectivities of the cycloadditions are controlled based on the ring size of the 2-cycloalkenones and the substitution patterns of the heptafulvenes. The chiral products obtained undergo various chemical and photochemical single-step transformations that give access to other classes of all-carbon polycyclic scaffolds.
Synthesis, structure, and reactivity of a gold carbenoid complex that lacks heteroatom stabilization
Harris, Robert J.,Widenhoefer, Ross A.
, p. 9369 - 9371,3 (2014)
Hydride abstraction from the neutral gold cycloheptatrienyl complex [(P)Au(η1-C7H7)] (P=P(tBu) 2(o-biphenyl)) with triphenylcarbenium tetrafluoroborate at -80 C led to the isolation of the cationic gold cycloheptatrienylidene complex [(P)Au(η1-C7H6)]+ BF 4- in 52 yield, which was characterized in solution and by single-crystal X-ray diffraction. This cycloheptatrienylidene complex represents the first example of a gold carbenoid complex that lacks conjugated heteroatom stabilization of the electron-deficient C1 carbon atom. The cycloheptatrienylidene ligand of this complex is reactive; it can be reduced by mild hydride donors, and converted to tropone in the presence of pyridine N-oxide. Hydride abstraction from the neutral gold cycloheptatrienyl complex 1 (P=P(tBu)2 (o-biphenyl)) with Ph3C+ BF 4- formed the cationic gold cycloheptatrienylidene complex 2, which was characterized by single-crystal X-ray diffraction. The cycloheptatrienylidene ligand of 2 is reactive; it can be reduced by mild hydride donors, and converted into tropone in the presence of pyridine N-oxide.
DDQ-mediated oxidative coupling reaction of N,N-dimethyl enaminones with cycloheptatriene
Cheng, Dongping,Yu, Chenze,Pu, Yueqi,Xu, Xiaoliang
supporting information, (2022/01/23)
An efficient 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated oxidative coupling reaction of N,N-dimethyl enaminones with cycloheptatriene is developed. It provides a variety of α-alkenylated 1,3-dicarbonyl compounds in moderate to good yields under mild conditions.
Continuous Endoperoxidation of Conjugated Dienes and Subsequent Rearrangements Leading to C-H Oxidized Synthons
De Souza, Juliana M.,Brocksom, Timothy J.,McQuade, D.Tyler,De Oliveira, Kleber T.
, p. 7574 - 7585 (2018/06/11)
We have investigated the continuous flow photooxidation of several conjugated dienes and subsequent rearrangement using a practical and safe continuous-flow homemade engineered setup. End-to-end approaches involving endoperoxidation, Kornblum-DeLaMare rearrangement, and additional rearrangements are comprehensively detailed with optimization, scope, and scale-up to obtain useful hydroxyenones, furans, and 1,4-dicarbonyl building blocks.
Dialkylated Dihydroazulene and Vinylheptafulvene Derivatives – Synthesis and Switching Properties
Lubrin, Nickie C. M.,Vlasceanu, Alexandru,Frandsen, Benjamin N.,Skov, Anders B.,Kilde, Martin Dr?hse,Mikkelsen, Kurt V.,Nielsen, Mogens Br?ndsted
supporting information, p. 2932 - 2939 (2017/06/06)
Functionalization of molecular photoswitches at specific positions offers a way of tuning their switching properties. The work presented here describes the development of a new protocol towards the synthesis and functionalization of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo-/thermoswitch. The key step is a facile condensation reaction using a functionalized tropone derivative, and the new synthetic method was employed in the regioselective preparation of a novel dimethyl-substituted DHA photoswitch. This compound presents the first accessible derivative with alkyl groups on the seven-membered ring of the system ― at positions C5 and C7. From experimental and theoretical kinetics studies on the thermal VHF-to-DHA electrocyclic reaction, the influence of the electron-donating methyl groups was elucidated. In addition, we subjected a small selection of 4,8a-dialkylated compounds to a computational study to elucidate how steric interactions can alter the relative DHA–VHF stabilities. The synthetic methodology offers access to novel DHA scaffolds and substitution patterns, which in turn can lead to systems that can help to address broader questions concerning the potential applicability of the DHA/VHF system in the context of solar-thermal energy-storage systems or other photochromic applications.
Phenylhydroxycarbene
Gerbig, Dennis,Reisenauer, Hans Peter,Wu, Chia-Hua,Ley, David,Allen, Wesley D.,Schreiner, Peter R.
supporting information; scheme or table, p. 7273 - 7275 (2010/07/14)
Phenylhydroxycarbene (Ph-C-OH, 1), the parent of all arylhydroxycarbenes, was generated by high-vacuum flash pyrolysis of phenylglyoxylic acid at 600 °C and spectroscopically characterized (IR, UV-vis) via immediate matrix isolation in solid Ar at 11 K. The identity of 1 was unequivocally confirmed by the precise agreement between the observed IR bands and (unscaled) anharmonic vibrational frequencies computed from a CCSD(T)/cc-pVDZ quartic force field. The UV-vis spectrum of 1 displays a broad band with maximum absorption at 500 25 nm (2.5 ± 0.1 eV) that extends to ～640 nm (1.9 eV), in full accord with combined CCSD(T)/cc-pVQZ and EOM-CCSD/cc-pVTZ computations that yield a gas-phase vertical (adiabatic) excitation energy of 2.7 (1.9) eV. Unlike singlet phenylchlorocarbene, 1 does not undergo photochemical ring expansion. Instead, 1 exhibits quantum-mechanical hydroGenetunneling to benzaldehyde underneath a formidable barrier of 28.8 kcal mol-1, even at cryogenic temperatures. The remarkable hydroGenetunneling mechanism is supported by the temperature insensitivity of the observed half-life (2.5 h) and substantiated by a comparable theoretical half-life (3.3 h) determined from high-level barrier penetration integrals computed along the intrinsic reaction path. As expected, deuteration turns off the tunneling mechanism, so d-1 is stable under otherwise identical conditions.
Homocoupling of halotropones promoted by bis(1,5-cyclooctadiene) nickel in the presence of tris(1-pyrazolyl)methane: an easy route to [Bi-1,3,5- cycloheptatrien-1-yl]-7,7'-diones
Funaioli, Tiziana,Cavazza, Marino
experimental part, p. 1592 - 1600 (2009/10/17)
An efficient homocoupling of 2-halotropones, to afford 2,2'-bitropones, occurs in toluene at rt in the presence of stoichiometric amounts of [Ni(cod)2] and tris(1-pyrazolyl)methane ligand, in a 1:1 molar ratio. This methodology was extended to aryl halides. Copyright Taylor & Francis Group, LLC.
Ring-expansion protocol: Preparation of synthetically versatile dihydrotropones
Do, Young-Sun,Sun, Ruiying,Kim, Hee Jin,Yeo, Jung Eun,Bae, Sung-Hee,Koo, Sangho
supporting information; experimental part, p. 917 - 920 (2009/06/20)
A ring-expansion protocol that consisted of the 1,2-addition of various enolate nucleophiles to 6-trimethylsiloxy-2- cyclohexene-1-one (1) and the NaIO4-promoted oxidative ring opening of the resulting diols 2, followed by an intramolecular Kno
