7339-99-3Relevant academic research and scientific papers
Photochemical Activation of Aromatic Aldehydes: Synthesis of Amides, Hydroxamic Acids and Esters
Nikitas, Nikolaos F.,Apostolopoulou, Mary K.,Skolia, Elpida,Tsoukaki, Anna,Kokotos, Christoforos G.
supporting information, p. 7915 - 7922 (2021/05/03)
A cheap, facile and metal-free photochemical protocol for the activation of aromatic aldehydes has been developed. Utilizing thioxanthen-9-one as the photocatalyst and cheap household lamps as the light source, a variety of aromatic aldehydes have been activated and subsequently converted in a one-pot reaction into amides, hydroxamic acids and esters in good to high yields. The applicability of this method was highlighted in the synthesis of Moclobemide, a drug against depression and social anxiety. Extended and detailed mechanistic studies have been conducted, in order to determine a plausible mechanism for the reaction.
An unexpected new pathway for nitroxide radical production via more reactve nitrogen-centered amidyl radical intermediate during detoxification of the carcinogenic halogenated quinones by N-alkyl hydroxamic acids
Zhu, Ben-Zhan,Xu, Dan,Qin, Li,Huang, Chun-Hua,Xie, Lin-Na,Mao, Li,Shao, Jie,Kalyanaraman, Balaraman
, p. 150 - 159 (2019/11/28)
We found previously that nitroxide radical of desferrioxamine (DFO?) could be produced from the interaction between the classic iron chelating agent desferrioxamine (DFO, an N-alkyl trihydroxamic acid) and tetrachlorohydroquinone (TCHQ), one of the carconogenic quinoind metabolites of the widely used wood preservative pentachlorophenol. However, the underlying molecular mechanism remains unclear. Here N-methylacetohydroxamic acid (N-MeAHA) was synthesized and used as a simple model compound of DFO for further mechanistic study. As expected, direct ESR studies showed that nitroxide radical of N-MeAHA (Ac-(CH3)NO?) can be produced from N-MeAHA/TCHQ. Interestingly and unexpectedly, when TCHQ was substituted by its oxidation product tetrachloro-1,4-benzoquinone (TCBQ), although Ac-(CH3)NO? could also be produced, no concurrent formation of tetrachlorosemiquinone radical (TCSQ?) and TCHQ was detected, suggesting that Ac-(CH3)NO? did not result from direct oxidation of N-MeAHA by TCSQ? or TCBQ as proposed previously. To our surprise, a new nitrogen-centered amidyl radical was found to be generated from N-MeAHA/TCBQ, which was observed by ESR with the spin-trapping agents and further unequivacally identified as Ac-(CH3)N? by HPLC-MS. The final product of amidyl radical was isolated and identified as its corresponding amine. Analogous radical homolysis mechanism was observed with other halogenated quinoid compounds and N-alkyl hydroxamic acids including DFO. Interestingly, amidyl radicals were found to induce both DNA strand breaks and DNA adduct formation, suggesting that N-alkyl hydroxamic acids may exert their potential side-toxic effects via forming the reactive amidyl radical species. This study represents the first report of an unexpected new pathway for nitroxide radical production via hydrogen abstration reaction of a more reactive amidyl radical intermediate during the detoxification of the carcinogenic polyhalogenated quinones by N-alkyl hydroxamic acids, which provides more direct experimental evidence to better explain not only our previous finding that excess DFO can provide effective but only partial protection against TCHQ (or TCBQ)-induced biological damage, and also the potential side-toxic effects induced by DFO and other N-alkyl hydroxamic acid drugs.
Access to Cyanoimines Enabled by Dual Photoredox/Copper-Catalyzed Cyanation of O-Acyl Oximes
Wei, Ziyan,Yu, Shouyun,Zhang, Ai Hua,Zhang, Hao
supporting information, p. 7315 - 7320 (2020/10/02)
An efficient strategy for the synthesis of pharmaceutically important and synthetically useful cyanoimines, as well as cyanamides, has been described. This strategy is enabled by dual photoredox/copper-catalyzed cyanation of O-acyl oximes or O-acyl hydroxamides. This state of the art protocol for cyanoimines and cyanamides features readily available starting materials, mild reaction conditions, good functional group tolerance, and operational simplicity. The resultant cyanoimines can be transformed into structurally diverse and functionally important N-containing heterocycles.
Direct and Selective 3-Amidation of Indoles Using Electrophilic N-[(Benzenesulfonyl)oxy]amides
Ortiz, Gerardo X.,Hemric, Brett N.,Wang, Qiu
supporting information, p. 1314 - 1317 (2017/03/23)
Selective C-H amidation of 1H-indoles at the C3 position is reported as a direct entry to biologically important 3-aminoindoles. This transformation is achieved using novel N-[(benzenesulfonyl)oxy]amides as electrophilic nitrogen agents in the presence of ZnCl2. Interestingly, analogous reactions in the absence of ZnCl2 resulted in the formation of indole aminal products.
Convenient preparation of O-linked polymer-bound N-substituted hydroxylamines, intermediates for synthesis of N-substituted hydroxamic acids
Robinson, Dale E.,Holladay, Mark W.
, p. 2777 - 2779 (2007/10/03)
An efficient procedure for preparation of O-linked polymer-bound N-substituted hydroxylamines by reduction of resin-bound oximes with borane·pyridine complex in the presence of dichloroacetic acid is reported. Other reducing systems commonly used for imine or oxime reduction were ineffective, including borane·pyridine in the presence of acetic acid. Oximes derived from a variety of aromatic and aliphatic aldehydes and ketones were successfully reduced. The N-substituted products were acylated and cleaved from resin to afford N-substituted hydroxamic acids.
SYNTHESIS of NOVEL N-(PRIMARY)ALKYLHYDROXAMIC ACIDS
Grierson, Lebert,Perkins, M. John
, p. 7463 - 7464 (2007/10/02)
Synthesis of N-primary alkylhydroxamic acids is described in this paper by benzoyloxylation (benzoyl peroxide) of n-alkylamine and modification of the usual reaction conditions to stabilise the N-alkyl-O-benzoylhydroxylamine as the hydrochloride; this cir
Preparation and Properties of Some Analogues of N-Benzylbenzohydroxamic Acid
Tandon, Usha,Sahu, Basant R.
, p. 433 - 434 (2007/10/02)
Eleven new analogues of N-benzylbenzohydroxamic acid (BBHA) have been prepared by the acylation of N-benzylhydroxylamine with suitable acid chlorides at low temperature in mixed diethyl ether and petroleum ether media containing an aqueous suspension of s
