Catalyst and solvent-free amidation of inactive esters of N-protected amino acids

Nadimpally, Krishna Chaitanya; Thalluri, Kishore; Palakurthy, Nani Babu; Saha, Abhijit; Mandal, Bhubaneswar

doi:10.1016/j.tetlet.2011.03.039

Cited by 21 publications

(18 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[106] This methodology using the same reaction condition was applicable to various other inactive esters commonly deployed as protecting groups. [106] This methodology using the same reaction condition was applicable to various other inactive esters commonly deployed as protecting groups.…”

Section: Conventional Heating and Room Temperaturementioning

confidence: 99%

Solvent‐Free and Catalysts‐Free Chemistry: A Benign Pathway to Sustainability

Gawande¹,

Bonifácio²,

Luque³

et al. 2013

ChemSusChem

278

122

View full text Add to dashboard Cite

In the past decade, alternative benign organic methodologies have become an imperative part of organic syntheses and chemical reactions. The various new and innovative sustainable organic reactions and methodologies using no solvents or catalysts and employing alternative energy inputs such as microwaves, sonication, conventional and room temperature heating conditions, mechanochemical mixing, and high-speed ball milling are discussed in detail. Environmentally benign and pharmaceutically important reactions such as multicomponent, condensation, and Michael addition reactions; ring opening of epoxides; and oxidation and other significant organic reactions are discussed. An overview of benign reactions through solvent- and catalyst-free (SF-CF) chemistry and a critical perspective on emerging synergies between SF-CF organic reactions are discussed.

show abstract

Section: Conventional Heating and Room Temperaturementioning

confidence: 99%

Solvent‐Free and Catalysts‐Free Chemistry: A Benign Pathway to Sustainability

Gawande¹,

Bonifácio²,

Luque³

et al. 2013

ChemSusChem

278

122

View full text Add to dashboard Cite

show abstract

“…For example, Mandal and coworkers have found that methyl, ethyl, allyl, and benzyl esters of N-protected amino acids react with primary or cyclic secondary amines under catalyst-and solvent-free conditions at 40°C to afford their corresponding amides in good yields. 123 Vinyl esters are often used in catalytic N-acylation reactions, with irreversible tautomerization of their enolic leaving groups to their keto forms facilitating amide formation. For example, Pelagalli et al have shown that isopropenyl acetate can be used to acetylate primary and secondary amines under catalyst and solvent-free conditions at 60°C ( Figure 27(b)).…”

Section: Estersmentioning

confidence: 99%

6.11 N-Acylation Reactions of Amines

Taylor

Bull

2014

Comprehensive Organic Synthesis II

View full text Add to dashboard Cite

“…Separation was performed on a silica column using automated flash chromatography with ethyl acetate, which gave the amide 3 (0.22 g, 84%) as a colorless crystalline material; mp 164-165°C (lit. 26 H-Phe-Tyr-Trp-Thr(PO 3 H 2 )-Ser-Arg-Gln-Pro-Asn-Lys-His-GluAsp-Val-Ala-Phe-Val-Thr-Arg-Gln-Pro-Asn-Lys-Val-OH 6…”

Section: N-cyclohexyl Hippuramidementioning

confidence: 99%

Mechanistic insight into benzenethiol catalyzed amide bond formations from thioesters and primary amines

2014

View full text Add to dashboard Cite

The influence of arylthiols on cysteine-free ligation, i.e. the reaction between an alkyl thioester and a primary amine forming an amide bond, was studied in a polar aprotic solvent. We reacted the ethylthioester of hippuric acid with cyclohexylamine in the absence or presence of various quantities of thiophenol (PhSH) in a slurry of disodium hydrogen phosphate in dry DMF. Quantitative conversions into the resulting amide were observed within a few hours in the presence of equimolar amounts of thiophenol. Ab initio calculations showed that the reaction mechanism in DMF is similar to the well-known aqueous reaction mechanism. The energy barrier of the catalyzed amidation reaction is approximately 40 kJ mol(-1) lower than the non-catalyzed amidation reaction. At least partially this can be explained by a hydrogen bond from the amine to the π-electrons of the thiophenol, stabilizing the transition state in the aromatic thioester amidation reaction. Under similar conditions, cysteine-free ligation was achieved by coupling a fully side-chain protected 15 amino acid phosphopeptide thioester to the free N-terminal of a side-chain protected 9 amino acid peptide producing the corresponding 24 amino acid phosphopeptide.

show abstract

Catalyst and solvent-free amidation of inactive esters of N-protected amino acids

Cited by 21 publications

References 33 publications

Solvent‐Free and Catalysts‐Free Chemistry: A Benign Pathway to Sustainability

Solvent‐Free and Catalysts‐Free Chemistry: A Benign Pathway to Sustainability

6.11 N-Acylation Reactions of Amines

Mechanistic insight into benzenethiol catalyzed amide bond formations from thioesters and primary amines

Contact Info

Product

Resources

About