Chemistry and Biology of Diazonamide A:  Second Total Synthesis and Biological Investigations

Nicolaou, K. C.; Hao, Junliang; Reddy, M. Venkat Ram; Rao, Paraselli Bheema; Rassias, Gerasimos A.; Snyder, Scott A.; Huang, Xianhai; Chen, David Y-K; Brenzovich, William E.; Giuseppone, Nicolas; O′Brate, Aurora; Giannakakou, Paraskevi

doi:10.1021/ja040093a

Cited by 167 publications

(70 citation statements)

References 28 publications

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“…The 1 H and 13 C NMR spectra given byNicolaou et al [20]. for this compound are in good accord with these results.2-Phenyl-5,6-dihydro-4H-cyclopenta[d]oxazole (3c) was obtained in 45% yield (42 mg) after heating aziridine 1c for 1 h at 180°C as a yellow oil.…”

supporting

confidence: 84%

Intra- and intermolecular thermal transformations of 2-acyl- and 2-alkoxycarbonyl-N-phthalimidoaziridines

Кузнецов

Voronin

2011

Chem Heterocycl Comp

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Heating 2-acyl-and 2-alkoxycarbonyl-N-phthalimidoaziridines leads to substituted oxazoles in 45-65% yield. Only esters of oxazolecarboxylic acids are formed when the aziridine contains acyl and alkoxy groups. The thermolysis of the same aziridines in the presence of N-phenylmaleimide and the dimethyl ester of acetylenedicarboxylic acid gives both oxazoles and the products of 1,3-dipolar cycloaddition from aziridines with two substituents at the carbon atoms but only oxazoles from trisubstituted aziridines.The thermally or photochemically induced dissociation of the C−C bond in the strained aziridine ring leads to 1,3-dipoles, which have been termed azomethinylids [1]. The addition of these species at multiple bonds of dipolarophiles yields various five-membered nitrogen heterocycles [2]. The generation of azomethinylids upon heating derivatives of N-phthalimidoaziridine and subsequent 1,3-dipolar cycloaddition have been demonstrated experimentally [3][4][5]. On the other hand, heating N-phthalimidoaziridines having acyl [6] or alkoxycarbonyl substituents [7] at the carbon atoms of the aziridine ring in the absence of dipolarophiles leads to oxazoles, which may be attributed to a 1,5-electrocyclization of the intermediate acylazomethinylids accompanied by loss of the phthalimide group.Thus, two types of thermal transformations are possible for acyl and alkoxycarbonyl derivatives of N-phthalimidoaziridine: 1) 1,3-dipolar cycloaddition and 2) rearrangement to give oxazoles. These reactions may compete and their preparative value will depend on which pathway predominates. In the present work, we studied both the intra-and intermolecular thermal transformations of 2-acyl-and 2-alkoxy-N-phthalimidoaziridines.We selected aziridines 1a-f for this study. The corresponding oxazole has already been obtained in 60% yield upon heating aziridine 1a [6]. However, the reaction of this aziridine with dipolarophiles has not been investigated. Aziridines 1b,c were selected in light of the possibility of obtaining not readily available spirofused heterocyclic structures as the result of 1,3-dipolar cycloaddition. We considered the possibility of _______ * Dedicated to Leonid Isaakovich Belen'kii on the occasion of his eightieth birthday.

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confidence: 84%

Intra- and intermolecular thermal transformations of 2-acyl- and 2-alkoxycarbonyl-N-phthalimidoaziridines

Кузнецов

Voronin

2011

Chem Heterocycl Comp

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“…To establish the above proposed correlation, the phenolic hydroxyl group in 33 was converted into its derived methoxymethyl ether 35 by treatment with MeOCH 2 Cl/NPr 2 i Et in dichloromethane at 0 °C, Scheme 6. Reduction of the methyl ester functionality in 35 was achieved by exposure of 35 to LiBH 4 /THF to give 36 (75%), which was converted into 37 by treatment with n-Bu 4 Since 37 has been converted into diazonamide A 1 in Nicolaou's first synthesis,4a,c this constitutes a formal total synthesis of 1.…”

Section: Resultsmentioning

confidence: 99%

An Expedient Formal Total Synthesis of (−)-Diazonamide A via a Powerful, Stereoselective O-Aryl to C-Aryl Migration To Form the C10 Quaternary Center

et al. 2007

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During the course of studies on the synthesis of diazonamide A 1 an unusual O-aryl into C-aryl rearrangement was discovered that allows partial control of the absolute stereochemistry of the C-10 quaternary stereogenic center. Treatment of 30 with TBAF/THF gave the O-tyrosine ethers 31 and 32 (1:1), which on heating each separately in chloroform at reflux rearranged to 33 and 34 in ratios of (84:16) and (56:44) respectively. This corresponds to a 70% yield of the correct C-10 stereoisomer 33 and a 30% yield of the wrong C-10 stereoisomer 34. Attempts to convert 34 into 33 by ipso-protonation and equilibriation were unsuccessful. Confirmation of the stereochemical outcome of the rearrangement was obtained by converting 33 into 37, an advanced intermediate in the first synthesis of diazonamide A by Nicolaou et al. It was also found that the success of the above rearrangement is sensitive to the protecting group on both the tryptophan nitrogen atom and the tyrosine nitrogen atom.

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“…[2][3][4] Various kinds of racemic primary and secondary amines have been submitted to non-enzymatic kinetic resolutions through N-acylation promoted by chiral nucleophilic catalysts to produce optically active amines (Schemes 1 a,c). [8,9] Although nucleophilic-catalystpromoted N-acylation has also been applied to the kinetic resolution of 2-amino-2'-hydroxy-1,1'-binaphthyl (NOBIN) derivatives, the acylations showed only modest selectivities (s = 1.4-4.4, Scheme 1 c) [5] and the catalytic kinetic resolution of these axially chiral compounds still remains a challenging task. [8,9] Although nucleophilic-catalystpromoted N-acylation has also been applied to the kinetic resolution of 2-amino-2'-hydroxy-1,1'-binaphthyl (NOBIN) derivatives, the acylations showed only modest selectivities (s = 1.4-4.4, Scheme 1 c) [5] and the catalytic kinetic resolution of these axially chiral compounds still remains a challenging task.…”

Section: Seiji Shirakawa Xiangfei Wu and Keiji Maruoka*mentioning

confidence: 99%

Kinetic Resolution of Axially Chiral 2‐Amino‐1,1′‐Biaryls by Phase‐Transfer‐Catalyzed N‐Allylation

2013

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Chemistry and Biology of Diazonamide A: Second Total Synthesis and Biological Investigations

Cited by 167 publications

References 28 publications

Intra- and intermolecular thermal transformations of 2-acyl- and 2-alkoxycarbonyl-N-phthalimidoaziridines

Intra- and intermolecular thermal transformations of 2-acyl- and 2-alkoxycarbonyl-N-phthalimidoaziridines

An Expedient Formal Total Synthesis of (−)-Diazonamide A via a Powerful, Stereoselective O-Aryl to C-Aryl Migration To Form the C10 Quaternary Center

Kinetic Resolution of Axially Chiral 2‐Amino‐1,1′‐Biaryls by Phase‐Transfer‐Catalyzed N‐Allylation

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