The Chemistry of Amine—Azide Interconversion: Catalytic Diazotransfer and Regioselective Azide Reduction.

Nyffeler, Paul T.; Liang, Chang-Hsing; Koeller, Kathryn M.; Wong, Chi‐Huey

doi:10.1002/chin.200302174

Cited by 22 publications

(32 citation statements)

References 1 publication

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“…Silver-catalyzed coupling 29,30 between 14 and 15, followed by hydrolysis of the resulting addition product (not shown), then provided the amino alcohol 16 as an inconsequential 2:1 mixture of diastereomers (stereochemistry not assigned). Wong diazo transfer 31,32 to 16 using imidazole sulfonyl azide 33 yielded the azido alcohol 17 (56% over three steps). Treatment of the diazo transfer product 17 with hydrochloric acid in dichloromethane-dioxane then formed the primary ammonium ion 12.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Reactivity of Precolibactin 886

Herzon¹,

Healy²,

wernke³

et al. 2019

Preprint

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<div>The clb gene cluster encodes the biosynthesis of metabolites known as precolibactins and colibactins. The clb pathway is found in gut commensal E. coli, and clb metabolites are thought to initiate colorectal cancer via DNA cross-linking. Precolibactin 886 (1) is one of the most complex isolated clb metabolites; it contains a 15-atom macrocycle and an unusual 5-hydroxy-3-oxazoline ring. Here we report confirmation of the structural assignment via a biomimetic synthesis of precolibactin 886 (1) proceeding through the amino alcohol 9. Double oxidation of 9 afforded the unstable α-ketoimine 2 which underwent macrocyclization to precolibactin 886 (1) upon HPLC purification (3% from 9). Studies of the putative precolibactin 886 (1) biosynthetic precursor 2, the model α-ketoimine 25, and the α-dicarbonyl 26 revealed that these compounds are susceptible to nucleophilic rupture of the C36–C37 bond. Moreover, cleavage of 2 produces other known clb metabolites or biosynthetic intermediates. This unexpected reactivity explains the difficulties in isolating full clb metabolites and accounts for the structure of a recently identified colibactin–adenine adduct. The colibactin peptidase ClbP deacylates synthetic precolibactin 886 (1) to form a non-genotoxic pyridone, suggesting precolibactin 886 (1) lies off-path of the major biosynthetic route.</div>

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Section: Resultsmentioning

confidence: 99%

Synthesis and Reactivity of Precolibactin 886

Herzon¹,

Healy²,

wernke³

et al. 2019

Preprint

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“…Nyffeler et al described the use of two catalysts, zinc chloride and copper sulfate [24]. In some cases, zinc chloride provided better results in yield and reaction time than copper sulfate.…”

Section: Batch Scalementioning

confidence: 98%

“…The most commonly used diazotransfer reagent is triflyl azide, which in neat form is highly explosive. Due to its reactive nature, it has a relatively short shelf life and needs to be prepared directly prior to use [24]. In 2007, Goddard-Borger and Stick invented a new diazotransfer reagent, imidazole-1-sulfonyl azide hydrochloride (2) [25], which is stable and easy to prepare, and eventually cheaper compared to triflyl azide.…”

Section: Introductionmentioning

confidence: 99%

Continuous flow azide formation: Optimization and scale-up

Delville

Nieuwland²,

Janssen

et al. 2011

Chemical Engineering Journal

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a b s t r a c tThe intrinsically small volumes and highly controlled reaction conditions render continuous flow microreactors ideal systems for the synthesis of potentially explosive compounds such as organic azides. In this article, we report the formation of benzyl azide from benzylamine using imidazole-1-sulfonyl azide hydrochloride as diazotransfer reagent. In a small scale (semi-automated) continuous flow setup the diazotransfer reaction was optimized using minimal amounts of reagents; less than 400 mg of benzylamine was required to perform 60 optimization reactions. The optimal reaction conditions were indentified to be room temperature, 600 s of residence time and an imidazole-1-sulfonyl hydrochloride to benzylamine stoichiometric ratio of 3 to 4. Furthermore, we successfully scaled up the reaction with a factor of 200 to gram scale using one single continuous flow reactor.

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“…Since a common way to modify iron oxide NP involves treatment with γ-aminopropyl triethoxysilane to give amino-functionalized MNP, these authors explored the possibility of generating azido functionalities from corresponding amines via Cu(II)-catalyzed diazo transfer (112) and their subsequent funtionalization via CuAAC. In this one-pot protocol, the Cu(I) species required for CuAAC are easily generated in situ by addition of sodium ascorbate to Cu(II) salts necessary for diazo transfer (biphasic CH 2 Cl 2 -H 2 O mixture).…”

Section: Magnetic Nanoparticlesmentioning

confidence: 99%

Click Chemistry for Drug Delivery Nanosystems

et al. 2011

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The purpose of this Expert Review is to discuss the impact of click chemistry in nanosized drug delivery systems. Since the introduction of the click concept by Sharpless and coworkers in 2001, numerous examples of click reactions have been reported for the preparation and functionalization of polymeric micelles and nanoparticles, liposomes and polymersomes, capsules, microspheres, metal and silica nanoparticles, carbon nanotubes and fullerenes, or bionanoparticles. Among these click processes, Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) has attracted most attention based on its high orthogonality, reliability, and experimental simplicity for non-specialists. A renewed interest in the use of efficient classical transformations has been also observed (e.g., thiol-ene coupling, Michael addition, Diels-Alder). Special emphasis is also devoted to critically discuss the click concept, as well as practical aspects of application of CuAAC to ensure efficient and harmless bioconjugation.

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The Chemistry of Amine—Azide Interconversion: Catalytic Diazotransfer and Regioselective Azide Reduction.

Abstract: For Abstract see ChemInform Abstract in Full Text.

Cited by 22 publications

References 1 publication

Synthesis and Reactivity of Precolibactin 886

Synthesis and Reactivity of Precolibactin 886

Continuous flow azide formation: Optimization and scale-up

Click Chemistry for Drug Delivery Nanosystems

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