Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

• Seungmin Lee,
• Minsuk Kim,
• Hyewon Han and
• Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

• advancements in the synthetic transformations of dioxazolones, with particular examples of copper salts. Keywords: amidation; copper salts; dioxazolones; electrophilic nitrogen; N-acyl nitrene; Introduction Dioxazolones, first synthesized and reported by Beck and co-workers [1], have been employed as

• , a plausible reaction pathway is described in Figure 6. Decarboxylation of dioxazolone in INT-22 forms the copper nitrene intermediate INT-23. The thiol then attacks the electrophilic nitrogen center of INT-23, which further leads to the formation of intermediate INT-24. Finally, the desired product

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• difluoroiodobenzene 10 is formed in situ, which is activated by HF. Two possible mechanisms were given for the synthesis of pyrrolidines 14, which are the same two proposed for the synthesis of piperidines 6 (Scheme 1). Either an alkene-activated iodonium is formed or an activated electrophilic nitrogen is generated

Solvent-dependent chemoselective synthesis of different isoquinolinones mediated by the hypervalent iodine(III) reagent PISA

• Ze-Nan Hu,
• Yan-Hui Wang,
• Jia-Bing Wu,
• Ze Chen,
• Dou Hong and
• Chi Zhang

Beilstein J. Org. Chem. 2024, 20, 1914–1921, doi:10.3762/bjoc.20.167

• then undergoes a proton shift to provide intermediate B. Intermediate B collapses via reductive elimination to give nitrenium ion C, along with the release of iodobenzene and sulfamate. Finally, nucleophilic attack of the olefin moiety of C on the electrophilic nitrogen atom, followed by the

A general and atom-efficient continuous-flow approach to prepare amines, amides and imines via reactive N-chloramines

• Katherine E. Jolley,
• Michael R. Chapman and
• A. John Blacker

Beilstein J. Org. Chem. 2018, 14, 2220–2228, doi:10.3762/bjoc.14.196

• Abstract Chloramines are an important class of reagents, providing a convenient source of chlorine or electrophilic nitrogen. However, the instability of these compounds is a problem which makes their isolation and handling difficult. To overcome these hazards, a continuous-flow approach is reported which

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• 10 minutes), and, most importantly, higher GD selectivity (63% compared to 45% after 30 minutes) under the same reaction conditions. In order to explain such a behavior, a cooperative mechanism for the ionic liquid catalysis was invoked, whereby the electrophilic nitrogen atom aids in activating the

Approaches to α-amino acids via rearrangement to electron-deficient nitrogen: Beckmann and Hofmann rearrangements of appropriate carboxyl-protected substrates

• Sosale Chandrasekhar and
• V. Mohana Rao

Beilstein J. Org. Chem. 2012, 8, 1393–1399, doi:10.3762/bjoc.8.161

• transformation of 1 to 5 indicates that 1 functions as a glycine enolate equivalent with the benzoylamino group in 5 being introduced in umpolung fashion (reaction involves the migration to an electrophilic nitrogen center). Hofmann rearrangement approach Our strategy was based on the known ethyl