Asymmetrically substituted diphenylcarbazones as chelate formers

Czech, N.; Friese, B.; Umland, F.

doi:10.1016/s0003-2670(01)84423-8

Cited by 6 publications

(1 citation statement)

References 7 publications

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“…Functionalized hydrazines 1h and 1m are commercially available. However, functionalized hydrazines 1a , 1b , , 1c , 1d , 1f , , 1g , 1i , , 1j , , 1k , , 1l , , 1n , , and 1o and N -carbonyl aryldizenes 2a , 2b , , 2c , 2d , 2f , , 2g , 2h , , 2i , , 2j , , 2k , , 2l , , 2m , , and 2o , were prepared according to literature procedures.…”

Section: Methodsmentioning

confidence: 99%

Sc(OTf)₃-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction

2022

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We disclose the first accomplishment of the azo-Povarov reaction involving Sc(OTf) 3 -catalyzed [4 + 2] annulations of N -carbonyl aryldiazenes with cyclopentadiene in chloroform, in which N -carbonyl aryldiazenes act as 4π-electron donors. Hence, this protocol offers a rapid access to an array of cinnoline derivatives in moderate to good yields for substrates over a wide scope. The synthetic potential of the protocol was achieved by the gram-scale reaction and further derivatization of the obtained polycyclic product.

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Section: Methodsmentioning

confidence: 99%

Sc(OTf)₃-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction

2022

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N

Macdonald¹,

Lingard²

1993

Dictionary of Analytical Reagents

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The System Boron-Oxygen

Heller

1986

B Boron Compounds

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earlier literature cited therein. All formulas including radicals are written according to IUPAC nomenclature [1). Boron Oxides The Boron Monoxide Radical, [BO)"The [BO)" radical is one of the fundamental species appearing as intermediates in oxidation reactions. Hot-pressed B4C was oxidized in wet nitrogen and/or wet air atmosphere at a water vapor pressure of 1.5 to 20 kPa and in dry air of 900 up to 1400·C. The oxidation of B 4 C by water vapor and dry air at 900·C results in a weight loss; hence, it is assumed that the formation of [BO]" (and/or HB02) seems to be the major reaction. The oxidation rate of B 4 C by water vapor at 900·C could be expressed by surface chemical reaction-controlled kinetics with an apparent activation energy of 200 kJ/mol [2).In the reaction of molecular oxygen with crystalline a-boron powder, oxygen atoms in concentrations exceeding the thermodynamical equilibrium value (above an inert surface) by four to seven orders of magnitude were observed. By the use of the resonance fluorescence of oxygen atoms between 350 and 1000 ·C, the proposed mechanism of the reaction is: ( Boron ignition and combustion with its surrounding atmosphere was studied by timeresolved emission spectroscopy in the range of 0.2 to 5.5 Ilm. In one experiment, boron powder was burned in an oxygen atmosphere with initiation by a pyrotechnic device. The energy transfer by the hot gases led to a glowing phase of the boron particles, which then changed to a high-temperature combustion and ended in a second glowing phase. The two glowing phases emitted continuous emission spectra, and the burning phase emitted the bands of [BO]" and [B02]". Another experimental setup was used to feed boron particles into a hot oxidizing atmosphere, which was provided by a propane-air flame. The reaction was observed by high-speed cinematography and time-resolved emission spectroscopy. The flame contained a small amount of background radiation, and the emitted bands Of [BO]

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Asymmetrically substituted diphenylcarbazones as chelate formers

Cited by 6 publications

References 7 publications

Sc(OTf)₃-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction

Sc(OTf)₃-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction

N

The System Boron-Oxygen

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Asymmetrically substituted diphenylcarbazones as chelate formers

Cited by 6 publications

References 7 publications

Sc(OTf)3-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction

Sc(OTf)3-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction

N

The System Boron-Oxygen

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Sc(OTf)₃-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction

Sc(OTf)₃-Mediated [4 + 2] Annulations of N-Carbonyl Aryldiazenes with Cyclopentadiene to Construct Cinnoline Derivatives: Azo-Povarov Reaction