Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• -catalyzed aziridination of styrene (22) by chloramine-T (23, NaCl=NTs) as a source of nitrene in acetonitrile (Figure 5) [40]. No aziridine product was formed either without any source of copper or in the presence of a different copper salt, such as CuCl, CuCl2·2H2O, or CuOTf. Calix[4]pyrrole itself is

• activates the Cu–Cl bond via chloride···calixpyrrole (N–H···Cl) hydrogen-bonding interactions toward the formation of the nitrene intermediate from chloramine-T (NaCl=NTs). Additionally, calix[4]pyrrole served as a phase-transfer catalyst in this reaction. Since chloramine-T had low solubility in

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• -dehydrative reaction of aldehydes with isocyanate analogs ([3] and references therein) (Scheme 1b) and an oxidative reaction of primary benzylic alcohols with sulfonamides or chloramine-T ([3] and references therein), and although they are elegant, they use substrates that are not readily accessible or toxic

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

• afford amides. Primary and secondary imines were produced under continuous conditions from the reaction of N-chloramines with base, with one example subsequently reduced under asymmetric conditions to produce a chiral amine in 94% ee. Keywords: continuous flow; CSTR; N-chloramine; synthetic methods

• products are fluids which are contacted with solid-supported reagents that after some time require regeneration, which is not convenient within chemical manufacture. Chloramine itself is unstable, though has been produced safely at large scale using continuous-flow methods; in fact, chloramine has been

• used as an intermediate in the manufacture of hydrazine using the Raschig process [12][13]. N-Alkyl-N-chloramines are equally unstable, yet have only been prepared in batch via reaction of a primary or secondary amine with Cl2 gas, N-chlorosuccinimide, chloramine-T or hypochlorite salts [14][15

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• . Mal and co-workers reported a metal free, solvent-free and room temperature synthesis of amide bonds at 62–75% yield under ball-milling (21 Hz) from aromatic aldehydes and N-chloramine in presence of 20 mol % of tetrabutylammonium iodide (TBAI) and 2.0 equiv of TBHP (Scheme 16) [79]. Aromatic

• acids [78]. Mechanochemical amidation reaction from aromatic aldehydes and N-chloramine [79]. Mechanochemical CDC between benzaldehydes and benzyl amines [81]. Mechanochemical protection of -NH2 and -COOH group of amino acids [85]. Mechanochemical Ritter reaction [87]. Mechanochemical synthesis of

Continuous formation of N-chloro-N,N-dialkylamine solutions in well-mixed meso-scale flow reactors

• A. John Blacker and
• Katherine E. Jolley

Beilstein J. Org. Chem. 2015, 11, 2408–2417, doi:10.3762/bjoc.11.262

• solutions of N,N-dialkyl-N-chloramines produced continuously will enable their use in tandem flow reactions with a range of nucleophilic substrates. Keywords: amine; biphasic; chloramine; chlorination; continuous flow chemistry; CSTR; static mixer; sodium hypochlorite; tube reactor; Introduction N

• -BuOCl in situ for chloramine formation, applying the methodology to a broad range of substrates in high yields [20]. Published literature on chloramine formation is limited to batch procedures, however, the use of continuous processes could offer significant advantages. Use of continuous flow reactors

• chloramine formation to be an energetic process with a significant associated exotherm illustrating the need for efficient temperature control during the reaction to ensure a safe process. In batch it would be necessary to cool the reaction with an ice bath or similar, however, the continuous reactors

Recent advances in copper-catalyzed C–H bond amidation

• Jie-Ping Wan and
• Yanfeng Jing

Beilstein J. Org. Chem. 2015, 11, 2209–2222, doi:10.3762/bjoc.11.240

• , previously prepared nitrene precursors such as ArI=NTs [47] or chloramine-T [48] were required. To design a facile amidation method using this strategy, Yu and co-worker [49] developed a new method for the synthesis of tosyl-amidated esters 20 via C–H sulfonamidation of cyclic esters 19 under catalysis of

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• systems which are found in streptorubin B and metacycloprodigiosin [148][149][150]. In this context, the cyclooctene 164 was reacted with the intermediate formed in situ from chloramine-T and elemental selenium [151] and yielded the allylic amine derivative 165 (75%). An N-alkylation with propargyl

Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds

• Gerold Heuger and
• Richard Göttlich

Beilstein J. Org. Chem. 2015, 11, 1226–1234, doi:10.3762/bjoc.11.136

• derivatives like Chloramine-T to alkenes have been described by Sharpless [28][29], Komatsu [30][31][32] and Dodd [33]. In these examples the nitrogen center carries no substituents, which limits the scope of the reactions. In our own studies we wanted to develop a radical addition, using amidyl radicals with

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• problem of unstability of chloramine phosphate (chloramidophos, see Figure 3) as a pesticide by the formation of 1:1 inclusion complexes with β-CD [49]. The formation of inclusion complex was proved by DSC, Fourier transform infrared and X-ray diffraction [50]. The binding constant was estimated at 203 M

Synthesis of chiral N-phosphoryl aziridines through enantioselective aziridination of alkenes with phosphoryl azide via Co(II)-based metalloradical catalysis

• Jingran Tao,
• Li-Mei Jin and
• X. Peter Zhang

Beilstein J. Org. Chem. 2014, 10, 1282–1289, doi:10.3762/bjoc.10.129

• chiral catalysts, such as Mn, Fe, Cu, Rh, Ru and Co complexes, have been demonstrated as effective catalysts in asymmetric olefin aziridination with various nitrene sources, including the widely used iminoiodanes and their in situ variants, chloramine-T, bromamine-T, tosyloxycarbamates and organic azides

Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester

• Sarah L. Harding,
• Sebastian M. Marcuccio and
• G. Paul Savage

Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67

• chemical shift of the C(H)=N proton [34]. Attempted methods for the chlorination of aryl aldoximes to aryl hydroximoyl chloride include the use of N-chlorosuccinimide [35], chloramine-T [36], biphasic sodium hypochlorite [37][38], and tert-butyl hypochlorite [39]. These methods led to either no reaction or

Synthesis of crispine A analogues via an intramolecular Schmidt reaction

• Ajoy Kapat,
• Ponminor Senthil Kumar and
• Sundarababu Baskaran

Beilstein J. Org. Chem. 2007, 3, No. 49, doi:10.1186/1860-5397-3-49

• developed for the synthesis of crispine A. [20][21][22][23][24][25][26][27][28] Interestingly, Schell and Smith reported the first synthesis of crispine A, even before its isolation, using the N-chloramine rearrangement reaction as a key step.[25] In order to understand the structure activity relationship

Synthesis of sulfonimidamides from sulfinamides by oxidation with N-chlorosuccinimide

• Olga García Mancheño and
• Carsten Bolm

Beilstein J. Org. Chem. 2007, 3, No. 25, doi:10.1186/1860-5397-3-25

• rather limited substrate scope. For example, chlorine [14][15][16][17] is preferred for N-alkyl sulfinamides, reacting very violently with N-aryl derivatives. N-chlorobenzotriazole [15][16][18] is less efficient with bulky amines, and with chloramine-T or -N[3][4][19] only N-tosyl or -nosyl

• sulfonimidamides can be obtained. In addition, an alternative route to the intermediate N-tosyl or -nosyl sulfonimidoyl chlorides involves the reaction of sulfinyl chlorides with chloramine-T or -N. In connection with our interest on the application of sulfonimidamides in organic synthesis,[20] we now aimed at

• halogenating agents was studied (Table 1). Starting point was the use of chloramine-T as the most common chlorinating reagent for such transformation. As hypothesized, the reaction involved the corresponding sulfonimidoyl chloride. Thus, in the reaction of 1a with chloramine-T in acetonitrile both