Photochemically Induced Single Electron Transfer Reactions of Benzils with Allylstannane. Direct Observation of Reactive Intermediates by ESR Method
作者:Kazuhiro Maruyama、Yoshihiro Matano
DOI:10.1246/bcsj.63.2218
日期:1990.8
Although the photochemically induced reaction of benzil with allyltrimethylstannane in benzene afforded α-allylbenzoin as a major product, benzil did not react thermally with the same reagent. An ESR observation disclosed that the benzil anion radical ion-paired upon contact with trimethylstannyl cation (BSnMe3) was generated during irradiation. Its structure was confirmed by the detection of satellite
尽管苄基与烯丙基三甲基锡烷在苯中的光化学诱导反应提供了 α-烯丙基安息香作为主要产物,但苄基不与相同的试剂发生热反应。ESR 观察表明,与三甲基甲锡基阳离子 (BSnMe3) 接触后会发生离子配对的苄基阴离子自由基是在辐射过程中产生的。它的结构通过检测锡同位素产生的卫星信号得到证实。此外,在含有苄基和烯丙基锡烷的固溶体在 77 K 光解过程中也观察到了三线态自由基对。该反应通过从烯丙基锡烷到光激发的苄基的单电子转移进行,然后断裂的 C-Sn 键烯丙基锡阳离子自由基。最终,
Photoinduced Platinum-Catalyzed Reductive Allylation of α-Diketones with Allylic Carbonates
作者:Junpei Shimosato、Masaya Sawamura、Yusuke Masuda
DOI:10.1021/acs.orglett.4c00091
日期:2024.3.15
A unique process for the photoinduced platinum-catalyzed reductiveallylation of α-diketones with allyliccarbonates has been developed. This allylation reaction was found to proceed selectively at the more electron-deficient carbonyl group of the diketone to afford an α-keto homoallylic alcohol. Such products could be further derivatized by transformation of the remaining carbonyl group. A mechanistic
tBuOK/TMSOK‐Mediated “Alkyl Halide to Alkyl Free Radical” Transformation for Transition‐Metal‐Free Benzoin α‐C—H Alkylation
作者:Zhouying Wang、Lu Gan、Zhibin Song、Yunyun Liu、Jie‐Ping Wan
DOI:10.1002/cjoc.202400664
日期:2024.12
(tBuOK or tBuONa) mediated generation of aryl freeradical from aryl iodide remarks a milestone discovery in the freeradical chemistry. However, the equivalent “alkyl halide to alkylfreeradical” transformation has not yet been realized in applicable synthesis by similar catalytic tactic. In this paper, the first practical “alkyl halide to alkylfreeradical” transformation mediated by tBuOK or TMSOK
Palladium-Catalyzed C-Allylation of Benzoins and an NHC-Catalyzed Three Component Coupling Derived Thereof: Compatibility of NHC- and Pd-Catalysts
作者:Raphaël Lebeuf、Keiichi Hirano、Frank Glorius
DOI:10.1021/ol801644f
日期:2008.10.2
A large range of benzoins was successfully applied as C-nucleophiles in the palladium-catalyzed allylic alkylation with several allyl acetates, resulting in functionalized tertiary homoallylic alcohols. A number of unsymmetrical benzoins can be coupled with high levels of regio- and chemoselectivity. Finally, the challenging compatibility of free N-heterocyclic carbenes with a palladium catalyst has been utilized in a number of metal- and organocatalyzed three-component coupling reactions.