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Volumn 60, Issue 30, 2004, Pages 6311-6318

Asymmetric nucleophilic substitution of α-bromo amides via dynamic kinetic resolution for the preparation of dipeptide analogues

Author keywords

Asymmetric syntheses; Dipeptide; Dynamic kinetic resolution; Nucleophilic substitution; Peptidimimetics

Indexed keywords

AMIDE; DIBENZYLAMINE; DIPEPTIDE DERIVATIVE;

EID: 3242785709     PISSN: 00404020     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tet.2004.05.094     Document Type: Article
Times cited : (23)

References (26)
  • 18
    • 3242747188 scopus 로고    scopus 로고
    • The low selectivities in the absence of TBAI observed in entries 10 and 11, Table 2 suggest the possibility that the leaving group in the nucleophilic substitution in the presence of TBAI is iodide rather than bromide. Further mechanistic investigation for details of the process is underway
    • The low selectivities in the absence of TBAI observed in entries 10 and 11, Table 2 suggest the possibility that the leaving group in the nucleophilic substitution in the presence of TBAI is iodide rather than bromide. Further mechanistic investigation for details of the process is underway
  • 19
    • 3242743421 scopus 로고    scopus 로고
    • Calculations are performed with a semiempirical approximation using AM1. The software used was Spartan 5.1, wavefunction, Inc
    • Calculations are performed with a semiempirical approximation using AM1. The software used was Spartan 5.1, wavefunction, Inc
  • 20
    • 3242801780 scopus 로고    scopus 로고
    • When nucleophiles such as benzylthiol, tritylthiol, sodium malonate, sodium azide, potassium acetate, potassium thioacetate and potassium phthalate were used for the reaction with 1b, the corresponding substitution products were obtained in 17-88% yields with diastereomeric ratios from 51:49 to 55:45
    • When nucleophiles such as benzylthiol, tritylthiol, sodium malonate, sodium azide, potassium acetate, potassium thioacetate and potassium phthalate were used for the reaction with 1b, the corresponding substitution products were obtained in 17-88% yields with diastereomeric ratios from 51:49 to 55:45
  • 25
    • 3242788472 scopus 로고    scopus 로고
    • This study has also shown some limitation of the method, as it cannot be extended to α-bromo α-alkyl acetamides successfully. The substitution reactions of α-bromo α-methyl acetamides derived from various L-amino acids are generally very slow and showed lower stereoselectivities (ca. 80:20 dr) under the same reaction condition. All tested reactions of α-bromo α-ethyl acetamides gave very poor yields and selectivities
    • This study has also shown some limitation of the method, as it cannot be extended to α-bromo α-alkyl acetamides successfully. The substitution reactions of α-bromo α-methyl acetamides derived from various L-amino acids are generally very slow and showed lower stereoselectivities (ca. 80:20 dr) under the same reaction condition. All tested reactions of α-bromo α-ethyl acetamides gave very poor yields and selectivities


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.