72229-75-5Relevant academic research and scientific papers
Thoination of N-alkyl-O-acyl hydroxamic acid derivatives via Lawesson's reagent
Al-Faiyz, Yasair S. S.
, (2021/10/02)
N-alkyl-O-acyl thiohydroxamic acid derivatives were prepared in good yields by the treatment of their parent hydroxamic acids with Lawesson's reagent. Some of these thiohydroxamic acid derivatives exhibit the ability to undergo rearrangement under basic c
A Cascade Process of Hydroxamates Renders 1,6-Dioxa-3,9-diazaspiro[44]nonane-2,8-diones
Nazarian, Zohreh,Forsyth, Craig M.
, p. 2081 - 2091 (2021/02/01)
A cascade route to 1,6-dioxa-3,9-diazaspiro[4.4]nonane-2,8-diones from N, O -diacyl hydroxylamines consisting of a two-step procedure is described. The key transformation is a [3,3]-sigmatropic rearrangement of N, O -diacyl hydroxylamines promoted by form
Base-promoted aromatic [3,3] sigmatropic rearrangement of N-acyl-O-arylhydroxylamine derivatives
Tayama, Eiji,Hirano, Kazuki
, p. 665 - 673 (2019/01/04)
The base-promoted aromatic [3,3] sigmatropic rearrangement of N-acyl-O-arylhydroxylamines giving α-(2-hydroxyphenyl)amides was successfully demonstrated. The substrates were prepared from N-substituted hydroxylamines by N-acylation followed by copper(I)-mediated O-arylation with boronic acids. Treatment of the substrates with lithium hexamethyldisilazide (LiHMDS) in THF at 0 °C to room temperature generated the corresponding amide enolates. The aromatic [3,3] rearrangement of the enolates provided the desired products in moderate to good yields. A crossover experiment produced only intramolecular products and clarified that the reaction proceeds via the aromatic [3,3] sigmatropic rearrangement, not a bond-cleavage–recombination process. Our method is a formal α-arylation of amides.
SUBSTITUTED 1,2,3,4-TETRAHYDROISOQUINOLINE DERIVATIVES
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Page/Page column 15-16, (2010/02/15)
The invention relates to novel 1,2,3,4-tetrahydroisoquinoline derivatives of formula (I) wherein R1, R2, R3 and X are as defined in the claims, and their use as active ingredients in the preparation of pharmaceutical compo
Base catalysed rearrangement of N-alkyl-O-acyl hydroxamic acids: Synthesis of 2-acyloxyamides
Clark, Andrew J.,Al-Faiyz, Yassair S.S.,Broadhurst, Michael J.,Patel, Divya,Peacock, Joanne L.
, p. 1117 - 1127 (2007/10/03)
Activated N-alkyl-O-acyl hydroxamic acid derivatives 21a-t undergo thermal and base catalysed rearrangement 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 O-acyl groups were tolerated in the reaction. The electronic nature of the O-acyl group was found to effect the rate of the rearrangement with electron withdrawing groups (211 and 21o) increasing the observed rate and electron donating groups (21m and 21n) decreasing the observed rate. Cross-over experiments with 21a and 21h indicated a mechanism involving the intermediacy of free acyloxy anions. The requirement of a readily enolisable proton adjacent to the carbonyl group of the amide was found to be neccessary for the rearrangement as 21r and 21t both failed to rearrange under the reaction conditions investigated.
Rearrangements of activated O-acyl hydroxamic acid derivatives
Al-Faiyz, Yasair S. S.,Clark, Andrew J.,Filik, Robert P.,Peacock, Joanne L.,Thomas, Gerry H.
, p. 1269 - 1272 (2007/10/03)
O-acyl hydroxamic acid derivatives (1a-d, 6a-c, 8a-b) undergo base catalysed rearrangement to give secondary 2-acyloxyamides (4a-d, 7a-c, 9a-b) in moderate to excellent yields (56-98%).
Anionic hetero[3,3] and [3,5][ rearrangements of hydroxylamine derivatives accompanied with N-O bond cleavage
Endo,Uchida,Hizatate,Shudo
, p. 1096 - 1105 (2007/10/02)
Aromatic and aliphatic N,O-divinylhydroxylamine systems generated in situ from hydroxylamine derivatives smoothly undergo [3,3] rearrangement. The base-catalyzed formation and rearrangement of enolates or dienolates of N-aryl-O-acylhydroxylamines, N,O-dia
α-lactam intermediates in base-promoted reactions of O-sulfonylated hydroxamic acids with nucleophiles
Hoffman, Robert V.,Nayyar, Naresh K.,Chen, Wenting
, p. 5031 - 5034 (2007/10/02)
The reaction of N-(sulfonyloxy) amides with bases proceeds by initial formation of an α-lactam intermediate. A primary kinetic deuterium isotope effect, kH/kD = 2.17, a leaving group effect, β1gCH3 = 0.50, and n
Base-Promoted Reaction of O-Sulfonylated Hydroxamic Acids with Nucleophiles. A New Mehtod for the Synthesis of α-Substituted Amides
Hoffman, Ribert V.,Nayyar, Naresh K.,Chen, Wenting
, p. 5700 - 5707 (2007/10/02)
Treatment of a series of hydroxamic acids 2 with mesyl chloride in the presence of 2 equiv of triethylamine at 0 deg C gives 2-chloroamides 3 in good yields.Use of a single equivalent of triethylamine gives the N-(mesyloxy)amides 1, which are versatile sy
