Pyrolysis of ketone N,N,N-trimethylhydrazonium fluoroborates. Evidence for the genesis of pyridines

Newkome, George R.; Fishel, D. L.

doi:10.1021/jo00974a011

Cited by 29 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The synthesis often involves harsh reaction conditions, many functional groups are not tolerated and the isolated yields are in many cases remarkably poor. Other known methods of achieving tpy derivatives are the Tohda [21] and the Sauer [22] methodologies, or even the pyrolysis of hydrazonium salts [23].…”

mentioning

confidence: 99%

Terpyridine derivatives functionalized with (hetero)aromatic groups and the corresponding Ru complexes: Synthesis and characterization as SHG chromophores

et al. 2018

View full text Add to dashboard Cite

Push-pull terpyridine derivatives 3 were synthesized and characterized in order to study the variations produced in their optical and electronic properties by linking different (hetero)aromatic electron donor moieties at 4′position of the electron deficient terpyridine moiety. The final donor-acceptor systems 3a-g were synthesized in fair to good yields by Kröhnke condensation of the precursor aldehydes 1, with 2-acetylpyridine 2. Hyper-Rayleigh scattering in dioxane solutions using a fundamental wavelength of 1064 nm was employed to evaluate their second-order nonlinear optical properties. Terpyridine derivative 3g functionalized with the 9-ethyl-9Hcarbazolyl group exhibited the largest first hyperpolarizability (β = 610 × 10 −30 esu, using the T convention) thus indicating its potential application as a second harmonic generation (SHG) chromophore. Terpyridine derivatives 3 were also used as ligands for the synthesis of novel [Ru II (tpy)(NCS) 3 ]complexes, prepared in good yields by a two-step procedure involving the preparation of [Ru III (tpy)(Cl 3 )] as intermediates. Ruthenium II complexes display a broad absorption in the visible range, accounting for their very dark color. Their redox behaviour is mainly characterized by the Ru II -Ru III oxidation and by the ligand-centered reduction, whose potentials can be finely tuned by the electronic properties of the aromatic substituents on the terpyridine ligand. Hyper-Rayleigh scattering in methanol solutions using a fundamental wavelength of 1064 nm was also employed to evaluate their second order nonlinear optical properties.

show abstract

mentioning

confidence: 99%

Terpyridine derivatives functionalized with (hetero)aromatic groups and the corresponding Ru complexes: Synthesis and characterization as SHG chromophores

et al. 2018

View full text Add to dashboard Cite

show abstract

“…An alternative synthesis of 20 involved the reaction of β-dimethylamino enone 18 , prepared by condensation of ketone 13 with Bredereck's reagent, with 13 and NH 4 BF 4 . Though limited to synthesis of symmetrical pyridines, the trimethylhydrazonium tetrafluoroborate pyrolysis method provided the simplest synthesis of 20 from ketone 13 . Quaternization of dimethylhydrazone 19 with trimethyloxonium BF 4 - (rather than methyl iodide 29 ) generated the pyrolysis precursor directly, saving an anion exchange step.…”

Section: Resultsmentioning

confidence: 99%

“…Residual solvent was removed at 0.5 mmHg, yielding 0.12 g (100%) of Mannich base 27 as a colorless solid, mp 99-100 °C. 1 5-Benzylidene-9-butyl-3-methylene-2,3,5,6,7,8-hexahydroacridin-4(1H)-one (29). A mixture of 4.34 g (11 mmol) of Mannich base 27 and 24 mL (55 g, 0.39 mol) of CH3I was stirred at room temperature for 30 min, and then excess CH3I was removed by rotary evaporation.…”

Section: Methods Bmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Architecture. 2.¹Synthesis and Metal Complexation of Heptacyclic Terpyridyl Molecular Clefts

et al. 1998

View full text Add to dashboard Cite

Methods are described for the synthesis of a series of functionalized derivatives of 9-butyl-1,2,3,4,5,6,7,8-octahydroacridine (9), a building block for several types of highly preorganized host compounds. A key intermediate is 5-benzylidene-9-butyl-2,3,5,6,7,8-hexahydroacridin-4(1H)-one ( 23), which can also be used in the syntheses of torands and hydrogen-bonding hexagonal lattice receptors. A tridentate cleft (20), consisting of 2,2′;6′,2′′-terpyridine imbedded in a heptacyclic framework, and a corresponding pentadentate diketone (6) were synthesized from 9 in five and seven steps, respectively. The picrate extraction method was used to estimate the solution stabilities of alkali metal complexes of heptacyclic terpyridyls 6 and 20, which was also compared with a flexible terpyridyl (37). Alkali metal complexes of both heptacyclic terpyridyls showed relatively high K s values, but low size selectivity. Pentadentate host 6 binds Na + and K + more strongly than do most hexadentate crown ethers; flexible tridentate analogue 37 failed to extract alkali metal picrates into chloroform. The complexation abilities of 6 and 20 are attributed to enforced orientation of functional group dipoles toward the center of the molecular cleft. Sodium and potassium picrate complexes of pentadentate cleft 6 were synthesized (1:1 stoichiometry), and a 2:1 complex of calcium triflate (6 2 ‚Ca(CF 3 SO 3 ) 2 ) was also prepared.The discovery of alkali metal complexation by crown ethers 2 foreshadowed development of several other host families, 3 including podands, cryptands, 4 lariat ethers, 5 spherands, 6 cryptahemispherands, 6c and torands. 7 The examples shown in Figure 1 illustrate the general trend toward ion encapsulation and ligand rigidity for cryptands, spherands and cryptaspherands, compared with crown ethers. These structural modifications generally produce higher selectivity and stronger binding of alkali metals

show abstract

“…Solvents were dried according to literature procedures. [21] The compounds 1 [22] and 22 [23] were prepared as described previously in the literature. Thin-layer chromatography (TLC) was carried out on aluminum sheets coated with silica-gel 60 (Merck 5554).…”

Section: Methodsmentioning

confidence: 99%

Self-Complementary [2]Catenanes and Their Related [3]Catenanes

et al. 2000

View full text Add to dashboard Cite

Three [3]catenanes with cavities large enough to accommodate aromatic guests have been designed and synthesized (yields = 5-20 %) by means of kinetically controlled self-assembly processes. The X-ray structural analysis of one of three [3]catenanes confirmed the presence of a rectangular cavity (dimensions = 7 x 11 A) lined by pi-electron-rich recognition sites and hydrogen-bond acceptor groups. In spite of their apparently ideal recognition features, none of these [3]catenanes bind guests incorporating a pi-electron-deficient bipyridinium unit. However, the template-directed syntheses of the [3]catenanes also produce, in yields of 2-23%, [2]catenanes incorporating a 1,5-dioxynaphtho[38]crown-10 interlocked with a bipyridinium-based tetracationic cyclophane. The X-ray structural analyses of two of these [2]catenanes revealed that a combination of [pi...pi] and [C-H...pi] interactions is responsible for the formation of supramolecular homodimers in the solid state. 1H NMR spectroscopic investigations of the four [2]catenanes demonstrated that supramolecular homodimers are also formed (Ka= 17-31M(-1), T= 185 K) in (CD3)2CO solutions. Dynamic 1H NMR spectroscopy revealed that the 1,5-dioxynaphtho[38]crown-10 and tetracationic cyclophane components in the four [2]catenanes and in the three [3]catenanes circumrotate (deltaGc(not equal to) = 9-14 kcal mol(-1)) through each other's cavity in (CD3)2CO. Similarly, the 1,5-dioxynaphthalene and the bipyridinium ring systems rotate (deltaGc(not equal to) =10-14 kcal mol(-1)) about their [O...O] and [N...N] axes, respectively, in solution.

show abstract

Pyrolysis of ketone N,N,N-trimethylhydrazonium fluoroborates. Evidence for the genesis of pyridines

Cited by 29 publications

References 0 publications

Terpyridine derivatives functionalized with (hetero)aromatic groups and the corresponding Ru complexes: Synthesis and characterization as SHG chromophores

Terpyridine derivatives functionalized with (hetero)aromatic groups and the corresponding Ru complexes: Synthesis and characterization as SHG chromophores

Molecular Architecture. 2.¹Synthesis and Metal Complexation of Heptacyclic Terpyridyl Molecular Clefts

Self-Complementary [2]Catenanes and Their Related [3]Catenanes

Contact Info

Product

Resources

About

Pyrolysis of ketone N,N,N-trimethylhydrazonium fluoroborates. Evidence for the genesis of pyridines

Cited by 29 publications

References 0 publications

Terpyridine derivatives functionalized with (hetero)aromatic groups and the corresponding Ru complexes: Synthesis and characterization as SHG chromophores

Terpyridine derivatives functionalized with (hetero)aromatic groups and the corresponding Ru complexes: Synthesis and characterization as SHG chromophores

Molecular Architecture. 2.1Synthesis and Metal Complexation of Heptacyclic Terpyridyl Molecular Clefts

Self-Complementary [2]Catenanes and Their Related [3]Catenanes

Contact Info

Product

Resources

About

Molecular Architecture. 2.¹Synthesis and Metal Complexation of Heptacyclic Terpyridyl Molecular Clefts