Base-promoted reaction of O-sulfonylated hydroxamic acids with nucleophiles. A new method for the synthesis of .alpha.-substituted amides
摘要:
Treatment of a series of hydroxamic acids 2 with mesyl chloride in the presence of 2 equiv of triethylamine at 0-degrees-C gives 2-chloroamides 3 in good yields. Use of a single equivalent of triethylamine gives the (N-mesyl-oxy)amides 1, which are versatile synthetic intermediates as they can be readily converted to 2-bromoamides 4 with lithium bromide and triethylamine and to 2-hydroxyamides 5 with triethylamine in aqueous acetonitrile.
Efficient conversion of O-sulfonylated arylacetohydroxamic acids to 2-substituted secondary amides
作者:Robert V. Hoffman、Naresh K. Nayyar、Bruce W. Klinekole
DOI:10.1021/ja00041a064
日期:1992.7
Base-promoted reaction of O-sulfonylated hydroxamic acids with nucleophiles. A new method for the synthesis of .alpha.-substituted amides
作者:Robert V. Hoffman、Naresh K. Nayyar、Wenting Chen
DOI:10.1021/jo00047a024
日期:1992.10
Treatment of a series of hydroxamic acids 2 with mesyl chloride in the presence of 2 equiv of triethylamine at 0-degrees-C gives 2-chloroamides 3 in good yields. Use of a single equivalent of triethylamine gives the (N-mesyl-oxy)amides 1, which are versatile synthetic intermediates as they can be readily converted to 2-bromoamides 4 with lithium bromide and triethylamine and to 2-hydroxyamides 5 with triethylamine in aqueous acetonitrile.
Base catalysed rearrangement of N-alkyl-O-acyl hydroxamic acids: synthesis of 2-acyloxyamides
作者:Andrew J. Clark、Yassair S. S. Al-Faiyz、Michael J. Broadhurst、Divya Patel、Joanne L. Peacock
DOI:10.1039/a909903d
日期:——
Activated N-alkyl-O-acyl hydroxamic acid derivatives 21a–t undergo thermal and basecatalysedrearrangement to give 2-acyloxyamides 22a–t in good to excellent yields (50–100%). A range of inorganic and organic bases were screened for their efficiency in mediating the rearrangement 21 to 22, however, simple organic bases such as Et3N were found to be the most efficient. Both aromatic and aliphatic derived