Die Synthese von ?-(o-Nitroaryl)-zimts�uren

Pailer, M.; Schleppnik, Alfred A.; Meller, A.

doi:10.1007/bf00898773

Cited by 3 publications

(4 citation statements)

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“…To a stirred solution of NaBH 4 (0.79 g, 21 mmol) in 25 mL of dry 1,2-dimethoxyethane at 0 °C under nitrogen was added dropwise titanium tetrachloride (0.76 mL, 7 mmol). The resultant mixture was stirred 10 min and then a solution of ( E )-2,3-bis( 2 -nitrophenyl)propenoic acid in 7 mL of dry 1,2-dimethoxyethane was added dropwise. The resultant mixture was stirred overnight.…”

Section: Methodsmentioning

confidence: 99%

New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and ¹H NMR) of Cyclic Carbodiimides

Molina¹,

Alajarı́n²,

Sánchez‐Andrada³

et al. 1996

J. Org. Chem.

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The crystal and molecular structure of carbodiimides 2 (5,6,18,19-tetradehydro-5,12,13,18,25,26-hexahydrotetrabenzo[d,h,m,q][1,3,10,12]tetraazacyclooctadecine) and 3 (8,10,22,24-tetraazapentacyclo[23.3.1.1(3,7).1(11,15).1(17,21)]dotriaconta-1(29),3,5,7(32),8,9,11,13,15(31),17,19,21(30),22,23,25,27-hexadecaene) have been determined. The activation barriers for the racemization of carbodiimides 1 (6,7-dihydrodibenzo[d,h][1,3]diazonine), 2, and 3 have been determined. While 1 presents a relatively high barrier (17.4 kcal mol(-)(1)), 2 and 3 have very low activation barriers (between 5 and 7 kcal mol(-)(1)). We tentatively conclude that open-chain and large-ring carbodiimides racemize by nitrogen inversion or trans-rotation while medium-size cyclic carbodiimides racemize by cis-rotation.

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Section: Methodsmentioning

confidence: 99%

New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and ¹H NMR) of Cyclic Carbodiimides

Molina¹,

Alajarı́n²,

Sánchez‐Andrada³

et al. 1996

J. Org. Chem.

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“…Condensation 16 of aldehyde 62 with acid 61, followed by carboxylic acid reduction, tert-butyldimethylsilyl (TBS) protection, and hydrogenation afforded cyclization precursor 63 in 53% yield over four steps. The oxidative cyclization of the dianiline 63 to diazocine 64 proceeded in 84% yield, which is virtually the same efficiency as that for the unsubstituted parent system.…”

Section: Journal Of the American Chemical Societymentioning

confidence: 99%

Oxidative Approach Enables Efficient Access to Cyclic Azobenzenes

et al. 2019

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Azobenzenes are versatile photoswitches that have found widespread use in a variety of fields, ranging from photopharmacology to the material sciences. In addition to regular azobenzenes, the cyclic diazocines have recently emerged. Although diazocines have fascinating conformational and photophysical properties, their use has been limited by their synthetic accessibility. Herein, we present a general, highyielding protocol that relies on the oxidative cyclization of dianilines. In combination with a modular substrate synthesis, it allows for rapid access to diversely functionalized diazocines on gram scales. Our work systematically explores substituent effects on the photoisomerization and thermal relaxation of diazocines. It will enable their incorporation into a wide variety of functional molecules, unlocking the full potential of these emerging photoswitches. The method can be applied to the synthesis of a new cyclic azobenzene with a nine-membered central ring and distinct properties.

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“…,, 5-SCH3, 3',4'-Cl, 180-182(C6H6) 706 C16HuC1,N04S S;CC Id 4-SCH3 2-NO" 3,5-Cl2 2-NO,, 3,5-Cl,, 4'-SCH3 142-153d (C6H6-petr ether) 70 In addition to C, H 6. From Ib.…”

mentioning

confidence: 99%

“…d Compound is a mixture of cis-and trans-cinnam- °From the sodium salt of aminocinnamic acid. 6 In addition to C, H. c Or the 6,7-dichloro isomer. d From methylthiophenanthroic acid.…”

mentioning

confidence: 99%

Antimalarials. 9. Methylthio- and methylsulfonyl-substituted 9-phenanthrenemethanols

Markovac¹,

Lamontagne²

1976

J. Med. Chem.

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Nine di- and trisubstituted 9-phenanthrenemethanols bearing methylthio and methylfulfonyl substituents in the 2 and/or 6 positions of the phenanthrene nucleus were prepared and screened for antimalarial activity against Plasmodium berghei in mice. Six of the nine compounds were curative at or below 160 mg/kg. The most active structures contained a methylthio substituent in combination with two chlorine atoms.

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Die Synthese von ?-(o-Nitroaryl)-zimts�uren

Cited by 3 publications

References 0 publications

New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and ¹H NMR) of Cyclic Carbodiimides

New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and ¹H NMR) of Cyclic Carbodiimides

Oxidative Approach Enables Efficient Access to Cyclic Azobenzenes

Antimalarials. 9. Methylthio- and methylsulfonyl-substituted 9-phenanthrenemethanols

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Die Synthese von ?-(o-Nitroaryl)-zimts�uren

Cited by 3 publications

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New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and 1H NMR) of Cyclic Carbodiimides

New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and 1H NMR) of Cyclic Carbodiimides

Oxidative Approach Enables Efficient Access to Cyclic Azobenzenes

Antimalarials. 9. Methylthio- and methylsulfonyl-substituted 9-phenanthrenemethanols

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Product

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New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and ¹H NMR) of Cyclic Carbodiimides

New Models for the Study of the Racemization Mechanism of Carbodiimides. Synthesis and Structure (X-ray Crystallography and ¹H NMR) of Cyclic Carbodiimides