Efficient nitrogen transfer from aldehyde-derived N-acyloxaziridines

Armstrong, Alan; Edmonds, Ian D.; Swarbrick, Martin E.

doi:10.1016/s0040-4039(03)01200-0

Cited by 38 publications

(11 citation statements)

References 11 publications

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“…1B). In accord with previously posited hypotheses (30, 31), this improvement likely results from increased stabilization of the transition state leading to intermediate A, which should be improved by solvation and hydrogen bonding to the developing alkoxy anion (Fig. 1C).…”

Section: Development Of React For Chemoselective Methionine Bioconjugsupporting

confidence: 88%

Redox-based reagents for chemoselective methionine bioconjugation

Lin

Yang

Jia

et al. 2017

Science

410

411

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Cysteine can be specifically functionalized by a myriad of acid-base conjugation strategies for applications ranging from probing protein function to antibody-drug conjugates and proteomics. In contrast, selective ligation to the other sulfur-containing amino acid, methionine, has been precluded by its intrinsically weaker nucleophilicity. Here, we report a strategy for chemoselective methionine bioconjugation through redox reactivity, using oxaziridine-based reagents to achieve highly selective, rapid, and robust methionine labeling under a range of biocompatible reaction conditions. We highlight the broad utility of this conjugation method to enable precise addition of payloads to proteins, synthesis of antibody-drug conjugates, and identification of hyperreactive methionine residues in whole proteomes.

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Section: Development Of React For Chemoselective Methionine Bioconjugsupporting

confidence: 88%

Redox-based reagents for chemoselective methionine bioconjugation

Lin

Yang

Jia

et al. 2017

Science

410

411

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“…S‐ protected cysteine‐derived nitrones ( S ‐Bn, S ‐ t Bu, S ‐trityl) are not suitable substrates for this transformation because of the decomposition of the oxaziridine intermediates 24. Despite this limitation, the substrate scope of this photochemical process represents a high degree of complementarity to NCL and allows peptide fragment coupling of a much broader range of amino acid residues.…”

Section: Methodsmentioning

confidence: 99%

Theoretical Study on the Mechanism of Ni‐Catalyzed Alkyl–Alkyl Suzuki Cross‐Coupling

Jiang

2012

Chemistry A European J

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Ni-catalyzed cross-coupling of unactivated secondary alkyl halides with alkylboranes provides an efficient way to construct alkyl-alkyl bonds. The mechanism of this reaction with the Ni/L1 (L1=trans-N,N'-dimethyl-1,2-cyclohexanediamine) system was examined for the first time by using theoretical calculations. The feasible mechanism was found to involve a Ni(I)-Ni(III) catalytic cycle with three main steps: transmetalation of [Ni(I)(L1)X] (X=Cl, Br) with 9-borabicyclo[3.3.1]nonane (9-BBN)R(1) to produce [Ni(I)(L1)(R(1))], oxidative addition of R(2) X with [Ni(I)(L1)(R(1))] to produce [Ni(III)(L1)(R(1))(R(2))X] through a radical pathway, and C-C reductive elimination to generate the product and [Ni(I)(L1)X]. The transmetalation step is rate-determining for both primary and secondary alkyl bromides. KOiBu decreases the activation barrier of the transmetalation step by forming a potassium alkyl boronate salt with alkyl borane. Tertiary alkyl halides are not reactive because the activation barrier of reductive elimination is too high (+34.7 kcal mol(-1)). On the other hand, the cross-coupling of alkyl chlorides can be catalyzed by Ni/L2 (L2=trans-N,N'-dimethyl-1,2-diphenylethane-1,2-diamine) because the activation barrier of transmetalation with L2 is lower than that with L1. Importantly, the Ni(0)-Ni(II) catalytic cycle is not favored in the present systems because reductive elimination from both singlet and triplet [Ni(II)(L1)(R(1))(R(2))] is very difficult.

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“…2 : 1) (Scheme 14). 30 Noteworthy, the results show that the stereochemical path was predominantly controlled by the absolute configuration of the ring carbon.…”

Section: Imidation With Oxaziridinesmentioning

confidence: 93%

Sulfur imidations: access to sulfimides and sulfoximines

2015

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Being mono-aza analogues of sulfoxides and sulfones, sulfimides and sulfoximines, respectively, are important compounds in asymmetric synthesis, crop protection and medicinal chemistry. For their preparation various methods have been developed. In the search for the optimal synthetic approach for a given target compound, several parameters have to be considered which also include safety issues and availability of starting materials. In this tutorial review, we present an overview of sulfur imidation methods, classified by imidating agents and compounds with a related behaviour. The aim of this survey is to provide a practical ''tool box'' for the synthetic chemist by mapping the advantages and disadvantages associated with the use of these compounds. Key learning points(1) Most imidating agents consist of the nitrogen atom to be transferred linked to a core fragment and a leaving group. (2) Sulfur imidation involves either the reaction between an electrophilic sulfonium salt and a nucleophilic nitrogen, or the addition of an electrophilic nitren(oid) species to a nucleophilic sulfur. (3) Toxicity and safety issues should be considered before choosing an imidation procedure. (4) Use of a catalytic amount of transition metal can considerably improve the imidation efficiency and allows stereoselective syntheses of sulfimides and sulfoximines.

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Efficient nitrogen transfer from aldehyde-derived N-acyloxaziridines

Cited by 38 publications

References 11 publications

Redox-based reagents for chemoselective methionine bioconjugation

Redox-based reagents for chemoselective methionine bioconjugation

Theoretical Study on the Mechanism of Ni‐Catalyzed Alkyl–Alkyl Suzuki Cross‐Coupling

Sulfur imidations: access to sulfimides and sulfoximines

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