Thiophenol-promoted radical chain reduction of .alpha.-substituted isobutyrophenones by 1,3-dimethyl-2-phenylbenzimidazoline
摘要:
The reductions of alpha-haloacetophenones and alpha-halopropiophenones by 1,3-dimethyl-2-phenylbenzimidazoline (DMBI) have been reported to proceed via an electron-transfer free-radical chain mechanism. The reduction of alpha-haloisobutyrophenones did not proceed by the chain sequence. We now report that initiated reductions of alpha-bromo- and alpha-chloroisobutyrophenones (IIIa,b) have been found to be promoted by the addition of thiophenol. Isobutyrophenone was formed as the major product via a free-radical chain process. During the PhSH-promoted DMBI reduction of IIIa,b a minor product, alpha-(phenylthio)isobutyrophenone (IV), was also formed via nucleophilic substitution. The chain propagation steps involve the efficient hydrogen atom transfers between PhCOCMe2. and PhSH and between PhS. and DMBI. The facile hydrogen transfer between PhS. and DMBI was confirmed by carrying out the radical-chain reduction of PhSSPh with DMBI.
Electron transfer processes. 34. Reactions of .alpha.-halo ketones with nucleophiles
作者:Glen A. Russell、Francisco Ros
DOI:10.1021/ja00294a050
日期:1985.4
On etudie les reactions des chlorures de p-nitro- ou p-cyano phenacyle ou de leurs derives dimethyl-1,1 avec divers nucleophiles
关于对硝基苯甲酰氯苯甲酰氯苯甲酰苯甲酰氯的研究反应,衍生二甲基-1,1 avec divers 亲核试剂
Copper‐Catalyzed Synthesis of
<i>gem</i>
‐Bisarylthio Enamines under Redox‐Neutral Conditions
作者:Jiabin Ni、Xiaokang Mao、Ao Zhang
DOI:10.1002/adsc.201900035
日期:2019.4.23
An efficient approach for the construction of gem‐bisarylthio enamines via coupling of oxime acetates with diaryldisulfides is developed. This process involved copper‐catalyzed N−O/S−S bond cleavages and formation of two new C−S bonds. A broad range of substrates with diverse functional groups were tolerated.
Visible light mediated reductions of ethers, amines and sulfides
作者:Timothy M. Monos、Gabriel Magallanes、Leanne J. Sebren、Corey R.J. Stephenson
DOI:10.1016/j.jphotochem.2016.05.014
日期:2016.9
Visible light-mediated photoredox catalysis enables the chemoselective reduction of activated carbon–heteroatom bonds as a function of reduction potential. The expansion of the scope of C–X bond reductions towards less activated motifs, such as ethers, amines and sulfides, is important to both organic synthesis and macromolecular degradation method development. In the present report, exploration of
of vinyl sulfides and unsaturated nitriles via quaternary phosphonium salts have been established. The reaction of isopropylidenetriphenylphosphorane with S-ethyl thiobenzoate or substituted S-ethyl thiobenzoates afforded vinyl sulfides and triphenylphosphine oxide in good yields. Further, it was found that the reaction of α-benzoylalkylphosphonium salts with sodium ethylmercaptide or potassium cyanide
Sulphurated derivatives of aromatic-aliphatic and aliphatic ketones as
申请人:Fratelli Lamberti S.p.A.
公开号:US05026740A1
公开(公告)日:1991-06-25
The invention relates to the use of a new class of sulphurated derivatives of aromatic-aliphatic or aliphatic ketones as a) polymerization or crosslinking photoinitiators for transparent or pigmented mixtures containing ethylenically unsaturated photopolymerizable compounds, in particular for obtaining polyacrylates, b) photochemically releasable latent acid catalysts, useful for crosslinking systems polycondensable by acid catalysis, of the type comprising etherified aminoplasts together with compounds containing hydroxyl, carboxyl, amido, amino and other functionalities. Said sulphurated derivatives enable manufactured articles to be obtained with exceptionally clear color while maintaining photochemical reactivity at high levels.