Polar effects in free radical reactions. Induced decompositions of peroxo compounds in the substitution of heteroaromatic bases by nucleophilic radicals
La decomposition des peroxydes de benzoyle etde lauroyle et du peroxodisulfate de potassium dans divers solvants conduit a une substitution selective en position 2 de la lepidine protonee par des radicaux libres nucleophiles generes dans les reactions (•CH 2 OH, dioxannyl, •CON(CH 3 ) 2 , CHON(CH 3 ) CH 2 • , (CH 3 ) 2 ĊH, cyclohexyl et n-C 11 H 23 •)
La 分解过氧化物苯甲酰和 de lauroyle et du peroxodisulfate de 钾 dans divers 溶剂导管 une 取代选择性 en position 2 de la lepidine protonee par des radicaux libres nucleophiles generices dans les 反应 (•CH 2 OH, 二恶尼基, •CON(CH) 3 ) 2 , CHON(CH 3 ) CH 2 • , (CH 3 ) 2 ĊH, 环己基等 nC 11 H 23 •)
Polar effects in free-radical reactions. New synthetic developments in the functionalization of heteroaromatic bases by nucleophilic radicals
nucleophilic carbon-centered radicals is furtheron developed by the following new achievements: i) utilization of the redoc system in several solvents; ii) utilization of benzoyl peroxide in alcohols; iii) carbamoylation by HCONH2 and H2O2 in the presence of catalytic amounts of Fe(II). These systems allow to obtain either substitution till now tried without success or reactions of industrial interest.
下列新成果进一步发展了质子化杂芳族碱基被亲核碳中心自由基直接取代的综合兴趣:ii)酒精中过氧化苯甲酰的利用;iii)在催化量的Fe(II)存在下通过HCONH 2和H 2 O 2进行氨基甲酰基化。这些系统允许获得直到现在为止一直没有成功的替代方案,或者获得工业利益的反应。极性效应在确定反应性,选择性和合成应用方面起主要作用;特别强调了吡啶基类型的强亲核中间基团在重新麦芽糖化步骤中的作用。
Redox-chain decomposition of hydroxylamine-O-sulphonic acid. A novel general source of nucleophilic radicals for the functionalization of heteroaromatic bases
Protonated heteroaromaticbases react with formamide, N,N-dimethylformamide, cyclic ethers, and methanol in the presence of hydroxylamine-O-sulphonicacid and catalytic amounts of an iron(II) salt to afford selective substitution by a redox chain process.
Pyridine <i>N</i>-oxides as HAT reagents for photochemical C–H functionalization of electron-deficient heteroarenes
作者:Łukasz W. Ciszewski、Dorota Gryko
DOI:10.1039/d2cc03772f
日期:——
PyridineN-oxides have only recently marked their presence in the photocatalysis field, mainly serving as oxypyridinium salt precursors. Herein, their unique reactivity as a hydrogen atom transfer reagent in photochemical, Minisci-type alkylation of electron-deficient heteroarenes is unveiled. The formation of an EDA complex between a heterocyclic substrate and N-oxide precludes the need for a photocatalyst
Polar effects in free-radical reactions. Carbamoylation and .alpha.-N-amidoalkylation of heteroaromatic bases by amides and hydroxylamine-O-sulfonic acid