3839-48-3Relevant articles and documents
A general entry to 10-halocolchicides and 9-haloisocolchicides
Cavazza, Marino,Pietra, Francesco
, p. 3405 - 3413 (1997)
Readily accessible 10-tosyloxycolchicide (1) and LiX (X=Cl or Br or I) in MeOH/BF3·Et2O at reflux give 10-chloro- (2), 10-bromo- (4), or 10-iodocolchicide (5), in good yields. 9-Chloro- (7) and 9-bromoisocolchidide (8) can be similarly obtained from 9-tosyloxyisocolchidide (6) and the method applies also to troponoids.
Nanoribbons with Nonalternant Topology from Fusion of Polyazulene: Carbon Allotropes beyond Graphene
Fan, Qitang,Martin-Jimenez, Daniel,Ebeling, Daniel,Krug, Claudio K.,Brechmann, Lea,Kohlmeyer, Corinna,Hilt, Gerhard,Hieringer, Wolfgang,Schirmeisen, André,Gottfried, J. Michael
, p. 17713 - 17720 (2019)
Various two-dimensional (2D) carbon allotropes with nonalternant topologies, such as pentaheptites and phagraphene, have been proposed. Predictions indicate that these metastable carbon polymorphs, which contain odd-numbered rings, possess unusual (opto)electronic properties. However, none of these materials has been achieved experimentally due to synthetic challenges. In this work, by using on-surface synthesis, nanoribbons of the nonalternant graphene allotropes, phagraphene and tetra-penta-hepta(TPH)-graphene, have been obtained by dehydrogenative C-C coupling of 2,6-polyazulene chains. These chains were formed in a preceding reaction step via on-surface Ullmann coupling of 2,6-dibromoazulene. Low-temperature scanning probe microscopies with CO-functionalized tips and density functional theory calculations have been used to elucidate their structural properties. The proposed synthesis of nonalternant carbon nanoribbons from the fusion of synthetic line-defects may pave the way for large-area preparation of novel 2D carbon allotropes.
Azulene-moiety-based ligand for the efficient sensitization of four near-infrared luminescent lanthanide cations: Nd3+, Er3+, Tm3+, and Yb3+
Zhang, Jian,Petoud, Stephane
, p. 1264 - 1272 (2008)
The ML4 complexes formed by reaction between the bidentate azulene-based ligand diethyl 2-hydroxyazulene-1,3-dicarboxylate (HAz) and several lanthanide cations (Pr3+, Nd3+, Gd3+, Ho3+, Er3+, Tm3+, Yb3+, and Lu 3+) have been synthesized and characterized by elemental analysis, FT-IR vibrational spectroscopy and electrospray ionization mass spectroscopy, Spectrophotometric titrations have revealed that four Az ligands react with one lanthanide cation to form the ML4 complex in solution. Studies of the luminescence properties of these ML4 complexes demonstrated that Az is an efficient sensitizer for four different near-infrared emitting lanthanide cations (Nd3+, Er3+, Tm3+, and Yb 3+); the resulting complexes have high quantum yield values in CH3CN. The near-infrared emission arising from Tm3+ is especially interesting for biologic imaging and bioanalytical applications since biological systems have minimal interaction with photons at this wavelength. Hydration numbers, representing the number of water molecules bound to the lanthanide cations, were obtained through luminescence lifetime measurements and indicated that no molecules of water/solvent are bound to the lanthanide cation in the ML4 complex in solution. The four coordinated ligands protect well the central luminescent lanthanide cation against non-radiative deactivation from solvent molecules.
Synthesis and Crystal Packing of trans-Bis(2-aminotroponato)palladium(II) Complexes Bearing Linear Alkyl Chains - Hard Lamellar Structures Self-Locked by Cross-Shaped Molecular Units
Komiya, Naruyoshi,Hori, Takao,Naito, Masaya,Naota, Takeshi
, p. 156 - 163 (2014)
The synthesis, structure, and three-dimensional lamellar array of a series of trans-bis(2-aminotroponato-κN,κO)palladium(II) complexes bearing linear alkyl chains (1a: n = 5; 1b: n = 8; 1c: n = 14; 1d: n = 16; 1e: n = 18, where n is the number of carbon atoms in the chain) attached to trans nitrogen donor atoms are described. The trans-coordination of the ligands, the cross-shaped molecular structures, and the crystal packing of 1b and 1c have been unequivocally established from single-crystal XRD studies. Highly regulated multilayered lamellar structures are observed for 1b and 1c, where every lamellar layer in the crystallographic ab plane, formed by π-stacking interactions of metal cores and van der Waals interactions between alkyl chains, is laminated alternately on the c axis with an orthogonal lamellar array of the identical unit. Powder XRD analysis showed that 1b-1e exhibit diffraction peaks attributed to periodic (n00) reflections of a typical lamellar structure. A linear correlation between the d-spacing and chain lengths in these compounds indicates that they form the same type of three-dimensional layer-by-layer structure of lamellar aggregates. The correlation between the cross-shaped molecular structures of 1b-1e and the dimensionality of molecular constraint in the crystal packing is discussed by comparison with those of rod-shaped analogues that exhibit high liquid crystallinity.
Copper-Catalyzed 3-Positional Amination of 2-Azulenols with O-Benzoylhydroxylamines
Li, Meng,Wang, Dong-Hui
, p. 6638 - 6641 (2021)
A copper-catalyzed ortho-selective amination of 2-azulenols with O-benzoylhydroxylamines (RR′N-OBz) to synthesize ortho-aminoazulenols is reported. A wide range of functional groups on amines are compatible, furnishing the corresponding amino-azulene deri
Electrophilic catalysis in nucleophilic substitution reactions in ionic liquids
Cavazza, Marino,Pietra, Francesco
, p. 3633 - 3634 (2004)
2-Chlorotropone was obtained from 2-tosyloxytropone in 88% yield in the recyclable ionic medium BMIMBF4/LiCl. That Li+ acts as a Lewis acid was proven by the lack of reactivity of 2-tosyloxytropone, under the above conditions, on replacing LiCl with NaCl or BMIMCl, or using BMIMCl alone, or a BMIMBF4/MeCN/KCl mixture. 2-Bromo- and 2-iodotropone were obtained along similar lines from LiBr or LiI, respectively, whereas LiF proved unreactive.
The Effect of Base and Nucleophile on the Nucleophilic Substitution of Methoxytropone Derivatives: An Easy Access to 4- And 5-Substituted Multifunctional Azulenes
Kumar, Neha R.,Agrawal, Abhijeet R.,Choudhury, Aditya,Zade, Sanjio S.
supporting information, p. 9029 - 9041 (2020/08/14)
The nucleophilic substitution on 3-substituted 2-methoxytropones to form azulenes is dependent on the nucleophile and base employed. With bulkier nucleophiles (ethyl/methyl cyanoacetate), the reaction proceeds with the abnormal nucleophilic substitution i
Compound, application thereof and organic photoelectric device containing azulene ring (by machine translation)
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Paragraph 0085-0087, (2019/10/01)
The invention provides a compound containing an azulene ring, application thereof and an organic photoelectric device comprising the compound. The azulene-containing compound is a compound having a structure of Formula I. The organic photoelectric device
Abnormal Nucleophilic Substitution on Methoxytropone Derivatives: Steric Strategy to Synthesize 5-Substituted Azulenes
Kumar, Neha Rani,Agrawal, Abhijeet R.,Zade, Sanjio S.
supporting information, p. 14064 - 14071 (2019/11/03)
Azulene is a non-alternant non-benzenoid aromatic system, and in turn, it possesses unusual photophysical properties. Azulene-based conjugated systems have received increasing interest in recent years as optoelectronic materials. Despite the routes availa
Syntheses and properties of linear π-conjugated molecules composed of 1-azaazulene and azulene
Ohtsu, Keito,Hayami, Ryohei,Sagawa, Takuya,Tsukada, Satoru,Yamamoto, Kazuki,Gunji, Takahiro
supporting information, (2019/10/14)
Two compounds, 6-(1-azaazulen-2-yl)ethynylazulene (8) and 6-(2-azulenyl)ethynylazulene (10), were synthesized using the Sonogashira-Hagihara cross-coupling reaction followed by decarboxylation with concentrated phosphoric acid. Compounds 8 and 10 were cha
