Synthesis of oleophilic electron-rich phenylhydrazines

Jankowiak, Aleksandra; Kaszyński, Piotr

doi:10.3762/bjoc.8.29

Cited by 9 publications

(9 citation statements)

References 39 publications

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“…Magnetic studies of 1 [10]d at 500 Oe revealed nearly ideal paramagnetic behavior in both the liquid crystalline and isotropic phases. Similar to previous observations for 1 [8]a, no abrupt changes were detected upon phase transitions, which indicates that the spins are isolated in both phases. 2 In contrast, a sample of 1 [8]b showed a small decrease of magnetization upon isotropic to mesophase transition.…”

Section: Magnetic and Photovoltaic Characterizationsupporting

confidence: 90%

“…Similar to previous observations for 1 [8]a, no abrupt changes were detected upon phase transitions, which indicates that the spins are isolated in both phases. 2 In contrast, a sample of 1 [8]b showed a small decrease of magnetization upon isotropic to mesophase transition. 3 Time-of-Flight (ToF) studies of an unaligned sample of 1 [10]d in cells of 12.5 mm or 4.75 mm gap (applied voltage of 30-50 kV cm À1 ) showed only a negligible transient photocurrent in the range of 80-30 C that was insufficient to calculate charge mobility.…”

Section: Magnetic and Photovoltaic Characterizationsupporting

confidence: 90%

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Liquid crystalline radicals: discotic behavior of unsymmetrical derivatives of 1,3,5-triphenyl-6-oxoverdazyl

et al. 2014

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A series of six 6-oxoverdazyl (1[10]) substituted with a total of three 3,4,5-tri(decyloxy)phenyl and/or 3,4,5-tri(decylsulfanyl)phenyl groups was investigated by thermal, XRD, spectroscopic, magnetic and photovoltaic methods. The compounds exhibit columnar hexagonal (1[10]c, Col h ), columnar hexagonal ordered (1[10]b, Col h(o) ), columnar hexagonal 3D (1[10]a, 1[10]e and 1[10]f, Col h(3D) ) or a sequence of two phases (1[10]b, Col h -Col h(3D) ). The mesophase structure and stability and also thermochromism were investigated as a function of the number and distribution of decyloxy and decylsulfanyl substituents in the molecule. Thermal analysis demonstrated that the presence of the 3,4,5-tri(decyloxy)phenyl substituent in the C(3) position increases the phase stability. Spectroscopic analysis showed that only alldecyloxy derivative 1[10]b exhibits a hypsochromic shift upon Col h(o) formation, while all other compounds in the series show a modest bathochromic shift in the columnar phase relative to the isotropic phase. Magnetization investigation of 1[10]d demonstrated the paramagnetic behavior of isolated spins in isotropic and columnar phases. Negligible photocurrent was detected for 1[10]d in the columnar phase.

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Section: Magnetic and Photovoltaic Characterizationsupporting

confidence: 90%

Section: Magnetic and Photovoltaic Characterizationsupporting

confidence: 90%

Liquid crystalline radicals: discotic behavior of unsymmetrical derivatives of 1,3,5-triphenyl-6-oxoverdazyl

et al. 2014

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“…Lithiation of 7* with tBuLi and reaction with di-tert-butyl azodicarboxylate (DTBAD) gave the protected hydrazine 8*, which was deprotected with trifluoromethanesulfonic acid (TfOH) to give the crude hydrazine 2*, according to a general procedure. [17] The bromide 7* was obtained by alkylation of 5-bromopyrogallol with tosylate 9*, which, in turn, was obtained from (S)-3,7-dimethyloctanol (ee >98%).…”

Section: Synthesismentioning

confidence: 99%

“…To a solution of carbamoyl chloride 5b or 5c [12] (0.5 mmol) in dry benzene (15 mL), a solution of freshly prepared 3,4,5-trioctyloxyphenylhydrazine [17] (2) or 3,4,5-tris((S)-3,7-dimethyloctyloxy)phenylhydrazine (2*, 0.6 mmol) and Et 3 N (0.65 mmol) in dry benzene (5 mL) was added. The mixture was stirred for 2 h at 50°C…”

Section: General Procedures For 6-oxoverdazylsmentioning

confidence: 99%

“…Following a general procedure, [17] to a solution of TfOH (5 mmol) in CF 3 CH 2 OH (1 mL), a solution of 1,2-bis(tert-butoxycarbonyl)-1-(3,4,5-tris((S)-3,7-dimethyloctyloxy)phenylhydrazine (8*, 1 mmol) in CH 2 Cl 2 (1 mL) was added under Ar at -40°C. The mixture was stirred for 2 min, washed with saturated NaHCO 3 , organic products were extracted (CH 2 Cl 2 ), extracts dried (Na 2 SO 4 ) and solvents evaporated to give crude deprotected hydrazine 2*, which was used quickly for further steps without purification: 1 4.6.…”

Section: 45-tris((s)-37-dimethyloctyloxy) Phenylhydrazine (2*)mentioning

confidence: 99%

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Chiral discotic derivatives of 1,3,5-triphenyl-6-oxoverdazyl radical

et al. 2014

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Two derivatives of 1,3,5-aryl-6-oxoverdazyl containing two 3,4,5-trioctyloxyphenyl and one 3,4,5-tri((S)-3,7-dimethyloctyloxy)phenyl group in position C(3) (1b) or N(1) (1c) were investigated by thermal, X-ray diffraction and magnetic methods. The results were compared to those obtained for achiral derivative 1a containing three 3,4,5-trioctyloxyphenyl groups. All three compounds exhibit an ordered columnar hexagonal phase, Col h(o) , and for chiral derivatives, 1b and 1c, a superstructure with doubled periodicity was found. The introduction of the three chiral alkoxy substituents in 1a lowered the mesophase stability by about 50 K and induced a Col h phase in 1c. Thermochromic analysis showed a hypsochromic shift upon formation of the Col h(o) phase similar for all three derivatives 1 (~0.3 eV), which coincides with a 5% drop in effective magnetic moment, μ eff , for 1c. Analysis of magnetisation data in a range of 2-370 K at 200 Oe revealed weak antiferromagnetic interactions (θ = -4 K) in the Col h(o) phase.

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Asymmetric organocatalytic α-amination of 2-oxindoles with bis(2,2,2-trichloroethyl)azo-dicarboxylate

Bondanza

Mandoli

2018

Tetrahedron Letters

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An enantioselective electrophilic amination of 3-substituted-2-oxindoles is reported, using bis(2,2,2-trichloroethyl)azo-dicarboxylate and commercially available Cinchona alkaloid organocatalysts. The best results were obtained in the reaction of 3-aryl substrates, with high to excellent yields (75% to quantitative) and good stereoselectivity (64-77% ee). Facile reductive conversion of the protected 3-hydrazino fragment into the corresponding primary amine was also demonstrated, to expand the synthetic flexibility of asymmetric electrophilic amination with azo-dicarboxylic esters en route to enantioenriched 3-amino-2-oxindoles. The absolute configuration of 3-amino-3-phenyl-2-oxindole was independently established by electronic circular dichroism (ECD), combined with time-dependent density functional theory (TDDFT). .

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Synthesis of oleophilic electron-rich phenylhydrazines

Cited by 9 publications

References 39 publications

Liquid crystalline radicals: discotic behavior of unsymmetrical derivatives of 1,3,5-triphenyl-6-oxoverdazyl

Liquid crystalline radicals: discotic behavior of unsymmetrical derivatives of 1,3,5-triphenyl-6-oxoverdazyl

Chiral discotic derivatives of 1,3,5-triphenyl-6-oxoverdazyl radical

Asymmetric organocatalytic α-amination of 2-oxindoles with bis(2,2,2-trichloroethyl)azo-dicarboxylate

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