Site-selective conversion of azido groups at carbonyl α-positions into oxime groups leading triazide to a triple click conjugation scaffold

Yokoi, Taiki; Ueda, Tomomi; Tanimoto, Hiroki; Morimoto, Tsumoru; Kakiuchi, Kiyomi

doi:10.1039/c8cc09415b

Cited by 32 publications

(14 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1,3] Among them, a-azido carbonyls bearing an electron-withdrawing oxo functionality at the adjacent position have received considerable attention because of their unique chemical behaviors and synthetic potential compared to simple alkyl azides. [4,5] In addition, aazido carbonyls could be readily converted to various heterocycles such as triazoles or imidazole carbonyls,o xazoles, pyrroles,p yridines,p yrazines,t etrazoles and oxadiazoles. [4,6] Especially, a-1,2,3-triazole carbonyls prepared from the corresponding a-azido carbonyls have recently received particular attentions as bioisosteres of amide bonds for the development of peptidomimetics.…”

Section: Introductionmentioning

confidence: 99%

Chemo‐ and Enantioselective Oxidative α‐Azidation of Carbonyl Compounds

et al. 2020

View full text Add to dashboard Cite

We report high‐performance I+/H2O2 catalysis for the oxidative or decarboxylative oxidative α‐azidation of carbonyl compounds by using sodium azide under biphasic neutral phase‐transfer conditions. To induce higher reactivity especially for the α‐azidation of 1,3‐dicarbonyl compounds, we designed a structurally compact isoindoline‐derived quaternary ammonium iodide catalyst bearing electron‐withdrawing groups. The nonproductive decomposition pathways of I+/H2O2 catalysis could be suppressed by the use of a catalytic amount of a radical‐trapping agent. This oxidative coupling tolerates a variety of functional groups and could be readily applied to the late‐stage α‐azidation of structurally diverse complex molecules. Moreover, we achieved the enantioselective α‐azidation of 1,3‐dicarbonyl compounds as the first successful example of enantioselective intermolecular oxidative coupling with a chiral hypoiodite catalyst.

show abstract

Section: Introductionmentioning

confidence: 99%

Chemo‐ and Enantioselective Oxidative α‐Azidation of Carbonyl Compounds

et al. 2020

View full text Add to dashboard Cite

show abstract

“…1 H NMR (600 MHz, DMSO) d 12.60 (s, 1H), 8.03 (s, 1H), 7.91 (d, J = 8.2 Hz, 2H), 7.34 (d, J = 7.5 Hz, 2H), 2.39 (s, 3H). 13 C NMR (151 MHz, DMSO) d 188.7, 148.2, 144.3, 133.9, 130.2 (2C), 129.5 (2C), 21.7.…”

Section: General Informationmentioning

confidence: 99%

“…12 Despite the advances in this field, these methods suffer from harsh reaction conditions and limitations due to pre-formation of silyl enol ethers from ketones, causing poor regioselectivity and poor chemoselectivity, and an avoidable extra step and poor functional group tolerance (Scheme 1c). 13 Therefore, it is highly important and desirable to develop an in situ formation of enolates and to use green reagents for the construction of functionalized α-oximino ketones.…”

Section: Introductionmentioning

confidence: 99%

Water-mediated decarboxylative radical nitrosation of β-keto acids with tert-butyl nitrite: access to α-oximino ketones

Jia

Han

et al. 2022

New J. Chem.

View full text Add to dashboard Cite

show abstract

“…Since our original description of the flow photoisomerization protocol, it has been employed by a number of groups for trans ‐cyclooctene synthesis with applications that include radiochemistry, cellular imaging, drug delivery and materials science . There have also been a number of modifications to the flow procedure that have been introduced.…”

Section: Figurementioning

confidence: 99%

Flow Photochemical Syntheses of trans‐Cyclooctenes and trans‐Cycloheptenes Driven by Metal Complexation

Pigga

Fox

2019

Israel Journal of Chemistry

View full text Add to dashboard Cite

trans-Cyclooctenes and trans-cycloheptenes have long been the subject of physical organic study, but the broader application had been limited by synthetic accessibility. This account describes the development of a general, flow photochemical method for the preparative synthesis of trans-cycloalkene derivatives. Here, photoisomerization takes place in a closed-loop flow reactor where the reaction mixture is continuously cycled through Ag(I) on silicagel. Selective complexation of the trans-isomer by Ag(I) during flow drives an otherwise unfavorable isomeric ratio toward the transisomer. Analogous photoreactions under batch-conditions are low yielding, and flow chemistry is necessary in order to obtain trans-cycloalkenes in preparatively useful yields. The applications of the method to bioorthogonal chemistry and stereospecific transannulation chemistry are described.The unusual reactivity and well-defined chiral structure of trans-cycloalkenes has made them attractive targets for synthesis for nearly 70 years. [1][2][3] For example, trans-cyclooctene possesses planar chirality and displays a high barrier to racemization (E a = 35.6 kcal/mol), [4] and the most stable "crown" conformer has an alternating sequence of equatorial and axial hydrogens that is akin to chair cyclohexane. [5][6] The double bond of trans-cyclooctene is twisted severely in the crown conformation, [7] and as a consequence the HOMO of trans-cyclooctene is relatively high in energy. [8] trans-Cycloheptene also has a rigid structure with a distorted alkene. [7] The double bonds of medium-ring trans-alkenes are twisted. [7] trans-Cycloalkenes display unusual reactivity in HOMOalkene controlled cycloaddition reactions with dienes, [9] 1,3dipoles [8] and ketenes. [10] Strained trans-cycloalkenes also serve as ligands for transition metals. [11][12][13][14][15][16] This reactivity profile has made trans-cycloalkanes interesting targets for applications in synthesis and biology.The broadest applications of trans-cycloalkenes are in the field of bioorthogonal chemistry. The inverse-electron demand Diels-Alder reaction between tetrazines and strained alkenes has a rich history in physical organic and synthetic chemistry (Figure 1). [17][18][19] In 2008, three groups described the bioorthogonal reactions of tetrazines with strained alkenes. [20][21][22] The variant introduced by our group that used trans-cyclooctene is marked by exceptionally rapid kinetics, with rate constants that can exceed 10 6 M À 1 s À 1 in the fastest cases. [23][24] With the advances including the development of fluorogenic tetrazines [25] and reactions in live cells [26] and animals, [27] the tetrazine ligation has become a widely used tool for applications that span chemical biology, biomedical imaging, and materials science. [28][29][30][31][32][33][34][35][36][37] This account describes the development of general, flow photochemical methods for the preparative synthesis of transcycloalkene derivatives and enabled applications in synthesis and bioorthogonal chemistry. Selectiv...

show abstract

Site-selective conversion of azido groups at carbonyl α-positions into oxime groups leading triazide to a triple click conjugation scaffold

Abstract: This paper reports the selective conversion of alkyl azido groups at the carbonyl α-position into oximes, and one-pot triple click conjugation is demonstrated.

Cited by 32 publications

References 45 publications

Chemo‐ and Enantioselective Oxidative α‐Azidation of Carbonyl Compounds

Chemo‐ and Enantioselective Oxidative α‐Azidation of Carbonyl Compounds

Water-mediated decarboxylative radical nitrosation of β-keto acids with tert-butyl nitrite: access to α-oximino ketones

Flow Photochemical Syntheses of trans‐Cyclooctenes and trans‐Cycloheptenes Driven by Metal Complexation

Contact Info

Product

Resources

About