A novel selective fragmentation of cycloalkanones by NaNO2/HCl has been established. The C–Cbond cleavage reaction proceeds smoothly under mild conditions, selectively affording versatile keto acids or oxime acids. The methodology can streamline the synthesis of valuable chiral molecules and isocoumarins from readily available feedstocks.
Visible-Light-Mediated α-Arylation of Enol Acetates Using Aryl Diazonium Salts
作者:Thea Hering、Durga Prasad Hari、Burkhard König
DOI:10.1021/jo301984p
日期:2012.11.16
light mediates efficiently the α-arylation of enol acetates by aryl diazonium salts under mild conditions using [Ru(bpy)3]Cl2 as a photoredox catalyst. The broad scope of the reaction toward various diazonium salts and enol acetates was explored. The application of this reaction in the concise synthesis of 2-substituted indoles was demonstrated
Nucleophilic addition of silyl enol ethers to aromatic nitro compounds: scope and mechanism of reaction
作者:T. V. RajanBabu、G. S. Reddy、Tadamichi Fukunaga
DOI:10.1021/ja00305a024
日期:1985.9
chloride are not displaced in the reaction, suggesting the absence of radical ion intermediates. Dihydroaromatic nitro derivatives can be isolated in some cases, such as anthracene and naphthalene systems which are less prone to rearomatize. The use of silicon reagents in organic synthesis has been ex- panding rapidly in the past few year^,^-^ and versatile methods for carbon-carbon bond formations have been
Aerobic, Transition-Metal-Free, Direct, and Regiospecific Mono-α-arylation of Ketones: Synthesis and Mechanism by DFT Calculations
作者:Qing-Long Xu、Hongyin Gao、Muhammed Yousufuddin、Daniel H. Ess、László Kürti
DOI:10.1021/ja4074563
日期:2013.9.25
We disclose a facile, aerobic, transition-metal-free, direct, and regiospecific mono-α-arylation of ketones to yield aryl benzyl and (cyclo)alkyl benzyl ketones with substitution patterns that are currently inaccessible or challenging to prepare using conventional methods. The transformation is operationally simple, scalable, and environmentally friendly. There is no need for pre-functionalization
我们公开了一种简便、有氧、无过渡金属、直接和区域特异性的酮单-α-芳基化,以产生芳基苄基和(环)烷基苄基酮,其取代模式目前无法使用常规方法制备或难以制备。转型操作简单、可扩展且环保。不需要预官能化(即α-卤化或甲硅烷基烯醇醚形成)或使用专门的芳基化剂(即二芳基碘盐)。DFT 计算表明,原位生成的烯醇化物与硝基芳烃直接形成 CC 键,然后进行区域选择性 O2 介导的 CH 氧化。
A NOVEL NUCLEOPHILIC SUBSTITUTION OF THE FORMYL GROUP IN p-NITROBENZALDEHYDE WITH SOME CARBANIONS
作者:Genji Iwasaki、Seitaro Saeki、Masatomo Hamana
DOI:10.1246/cl.1986.173
日期:1986.2.5
p-Nitrobenzaldehyde reacts with some active methylene compounds in the presence of a strong base at low temperatures to give p-substituted nitrobenzenes by the two-step course involving the initial formation of the aldol adducts and the subsequent displacement of the carbinol moieties with excess carbanions.