Study of exchange reaction between 4-dimethylaminopyridine, N-methylimidazole, and their N-acyl salts in acetonitrile

Semenova, R. G.; Рыбаченко, В. И.; Титов, Е. В.

doi:10.1007/bf00592821

Cited by 2 publications

(2 citation statements)

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“…17 In addition, Semenova et al speculated that DMAP is more nucleophilic than NMI in acylation. 24 According to these previous reports, it is conceivable that the concentration of acyl ammonium cations in reactions between acylating agents and aromatic amines becomes lower in the order DMAP ≥ NMI ＞＞ pyridine. However, this trend seemed not to t with observations (Figure 4).…”

Section: Acylation Of α ─ Nca Via Simultaneous and Rapid Dualmentioning

confidence: 99%

“…Semenova et al speculated that acyl N ─ methylimidazolium cation is more electrophilic than acyl N,N ─ dimethylaminopyridinium cation. 24 Also, Guibé─ Jampel and Wakselman reported that the hydrolysis rate of acyl pyridinium cation is 2000 times faster than that of acyl N,N ─ dimethylaminopyridinium cation. 25 According to these previous reports, it is conceivable that the electrophilicity of the acyl ammonium cations becomes lower in the order pyridine ＞ NMI ＞ DMAP, i.e., opposite to the order of acyl ammonium cation concentration.…”

Section: Acylation Of α ─ Nca Via Simultaneous and Rapid Dualmentioning

confidence: 99%

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Micro-Flow N-Acylation Using Highly Electrophilic Acyl Ammonium Cations for Peptide and Urethane-Protected N-Carboxyanhydride Syntheses

Masui¹,

Fuse

2022

J. Synth. Org. Chem. Jpn.

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Acyl ammonium cations can be readily prepared from inexpensive and commercially available nucleophilic tertiary amines and acid chlorides or chloroformates. The signi cantly electrophilic nature of these cations allows rapid acylations to occur. However, it also causes undesired reactions. The emergence of micro─ ow technologies has enabled precise control of reaction time (＜ 1 s) and temperature that cannot be achieved by conventional batch technologies. In this account, we describe high─ yielding, rapid, less wasteful, and low─ cost syntheses of peptides and amino acid derivatives via highly electrophilic acyl ammonium cations in which undesired reactions were suppressed by micro─ ow technologies. These technologies not only enabled the development of highly ef cient synthetic processes, but also provided us deeper insights into the highly active acyl ammonium cation species involved. This is leading to novel discoveries regarding their value in synthesis.986 Scheme 2. The rst chemical peptide bond formation reported by Curtius in 1881.

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Section: Acylation Of α ─ Nca Via Simultaneous and Rapid Dualmentioning

confidence: 99%

Section: Acylation Of α ─ Nca Via Simultaneous and Rapid Dualmentioning

confidence: 99%