111750-23-3Relevant academic research and scientific papers
Visible-Light Induced C(sp2)?H Amidation with an Aryl–Alkyl σ-Bond Relocation via Redox-Neutral Radical–Polar Crossover
Chang, Sukbok,Jeong, Jiwoo,Jung, Hoimin,Keum, Hyeyun,Kim, Dongwook
supporting information, p. 25235 - 25240 (2021/10/25)
We report an approach for the intramolecular C(sp2)?H amidation of N-acyloxyamides under photoredox conditions to produce δ-benzolactams with an aryl-alkyl σ-bond relocation. Computational studies on the designed reductive single electron transfer strategy led us to identify N-[3,5-bis(trifluoromethyl)benzoyl] group as the most effective amidyl radical precursor. Upon the formation of an azaspirocyclic radical intermediate by the selective ipso-addition with outcompeting an ortho-attack, radical–polar crossover was then rationalized to lead to the rearomative ring-expansion with preferential C?C bond migration.
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.
Oxidative cleavage of hydroxamic acid promoted by sodium periodate
Yuan, Changchun,Du, Biao,Xun, Miao-Miao,Liu, Bo
, p. 3622 - 3628 (2017/06/13)
A series of hydroxamic acids, involving aliphatic, aromatic and cyclic substrates, were transformed to the corresponding carboxylic acids through NaIO4-mediated oxidative cleavage in mild conditions. Esterification of these acids with TMSCHN2 could result in formation of the corresponding methyl ester. This methodology makes good compensation for the existing methods transforming amides to esters. Our results also pave the way to harness hydroxamic acids as useful synthetic building blocks.
A Facile Preparation of N-(Isopropoxyalkyl) Amides by Generation and Trapping of N-Acyliminium Ions from Ionization-Rearrangement Reactions of N-Triflyloxy Amides
Hoffman, Robert V.,Nayyar, Naresh K.
, p. 3530 - 3539 (2007/10/02)
A series of hydroxamic acids were converted to N-triflyloxy amides which were heated in 2-propanol to give N-(1-isopropoxyalkyl) amides in high yields.The method is simple, direct, and extremely tolerant of structural diversity both in the N-acyl group, a
