PhSeSiR<sub>3</sub>-Catalyzed Group Transfer Radical Reactions
作者:Ganesh Pandey、K. S. S. P. Rao、K. V. Nageshwar Rao
DOI:10.1021/jo000128z
日期:2000.7.1
A novel design for initiating radical-based chemistry in a catalytic fashion is described. The design of the concept is based on the phenylselenyl group transfer reaction from alkyl phenyl selenides by utilizing PhSeSiR3 (1) as a catalytic reagent. The reaction is initiated by the homolytic cleavage of -C-Se- bond of an alkyl phenyl selenide by the in situ generated alkylsilyl radical (R3Si.), obtained by the mesolysis of PhSeSiR3](.-) (1(.-)). The oxidative dimerization of counteranion PhSe- to PhSeSePh functions as radical terminator. The generation of 1(.-) is achieved by the photoinduced electron transfer (PET) promoted reductive activation of 1 through a photosystem comprising of a visible-light (410 nm)-absorbing electron rich DMA as an electron donor and ascorbic acid as a co-oxidant (Figure 1). The optimum mole ratio between the catalyst 1 and alkyl phenyl selenides for successful reaction is established to be 1:10. The generality of the concept is demonstrated by carrying out variety of radical reactions such as cyclization (10, 15-18), intermolecular addition (25), and tandem annulations (32).
A Radical Addition/Cyclization and Se‐Group Transfer Strategy for the Facile Synthesis of Se‐Containing Cyclopentenes under Metal‐Free and Peroxide‐Free Conditions
作者:Dian‐Liang Wang、Nan‐Quan Jiang、Zhong‐Jian Cai、Shun‐Jun Ji
DOI:10.1002/chem.202103334
日期:2021.12.20
A highly atom-economic intermolecular radicaladdition/cyclization and Se-group transfer strategy was developed for the efficient synthesis of Se-containing cyclopentenes under metal-free and peroxide-free conditions.