Enantioselective Synthesis of γ-Oxycarbonyl Motifs by Conjugate Addition of Photogenerated α-Alkoxy Radicals
作者:Xiao Dong、Qi Yukki Li、Tehshik P. Yoon
DOI:10.1021/acs.orglett.1c01790
日期:2021.8.6
addition of photogenerated α-alkoxy radicals to acyl pyrazolidinones can be accomplished using a tandem Sc(III) Lewis acid/photoredox catalyst system. Surprisingly, the excited-state oxidation potential was not the only important variable, and the optimal photocatalyst was not the strongest oxidant screened. Our results show that both the oxidation and reduction potentials of the photocatalyst can be
可以使用串联的 Sc(III) Lewis 酸/光氧化还原催化剂体系实现对映选择性催化 Giese 将光生 α-烷氧基自由基加成到酰基吡唑烷酮。令人惊讶的是,激发态氧化电位并不是唯一重要的变量,最佳光催化剂也不是筛选出的最强氧化剂。我们的结果表明,光催化剂的氧化和还原电位对反应结果都很重要,突出了整体考虑在设计光化学反应中的重要性。
Metal-free desilylative C–C bond formation by visible-light photoredox catalysis
作者:Mustafa Uygur、Tobias Danelzik、Olga García Mancheño
DOI:10.1039/c8cc10239b
日期:——
A novel metal-free desilylative C–C bond formation from simple organosilanes by visible-light acridinium photoredox catalysis is presented.
通过可见光吖啶光还原催化,实现了从简单有机硅烷中无金属参与的脱硅碳-碳键形成。
Electro-initiated Coupling Reactions of<i>N</i>-Acyliminium Ion Pools with Arylthiomethylsilanes and Aryloxymethylsilanes
作者:Seiji Suga、Ikuo Shimizu、Yosuke Ashikari、Yusuke Mizuno、Tomokazu Maruyama、Jun-ichi Yoshida
DOI:10.1246/cl.2008.1008
日期:2008.9.5
Electro-initiated coupling reactions of N-acyliminium ion with arylthiomethylsilanes and aryloxymethylsilanes were developed. Pulse electrolyses with intervals were found to be quite effective for the initiation. A chain mechanism involving cation, radical cation, and radical intermediates has been proposed.
Pentacoordinate silicon intermediates in relay substitution reactions of organosilanes: successive nucleophilic attack at silicon and its adjacent carbon
作者:John J. Eisch、Chingchen S. Chiu
DOI:10.1016/0022-328x(88)87105-5
日期:1988.12
directly, FSiR2CH2EPh. This possibility of directing nucleophilicattack toward silicon or its adjacent carbon has great importance in the synthesis of substituted organosilanes. The mechanism of these so-called relay nucleophilicsubstitutions is proposed as involving pentacoordinate silicon intermediates. This concept of initial nucleophilicattack at silicon and the subsequent relaying of the nucleophile
已显示,ClCH 2 R 2 SiCl类型的氯甲基甲硅烷基氯与酚或胺(PhEH,具有EO或NMe)一起在硅上受到动力学控制的亲核攻击,从而产生PhESiR 2 CH类型的产物2 Cl。随后的产物用乙腈中的KF处理会导致亲核试剂从硅转移到碳,并形成FSiR 2 CH 2 EPh。或者,与PhEH和KF同时处理ClCH 2 R 2 SiCl会直接产生相同的热力学控制产物FSiR 2 CH 2EPh。将亲核攻击指向硅或其相邻碳的可能性在合成取代的有机硅烷中非常重要。这些所谓的中继亲核取代的机理被认为涉及五配位硅中间体。最初的亲核攻击是在硅上发生,随后亲核剂从五配位硅转移到相邻碳原子的概念也显示适用于α,β-环氧烷基硅烷的异常反应。
Chromium/Photoredox Dual Catalyzed Synthesis of
<i>α</i>
‐Benzylic Alcohols, Isochromanones, 1,2‐Oxy Alcohols and 1,2‐Thio Alcohols
作者:Subhabrata Dutta、Johannes E. Erchinger、Felix Schäfers、Ankita Das、Constantin G. Daniliuc、Frank Glorius
DOI:10.1002/anie.202212136
日期:2022.12.5
The synthesis of α-benzylic alcohols, functionalized isochromanones, 1,2-oxy alcohols and 1,2-thio alcohols has been successfully achieved by employing a dual catalytic method combining chromium chemistry and photoredox catalysis. This presents a methodology under mild conditions with high functional group tolerance.