methylene compounds has been developed. Aryl substituted alkenes and an aliphatic diene can be used as alkyl sources for these reactions, which proceed via polycyanoarene sensitized, photoinduced electron transfer pathways that are promoted using very mild conditions (ambient temperature, without noble metals and halogens, and with weak bases such as alkali metal carbonate). The reactions that comprise the
without metals and halogens, and in the presence of weak base. The reaction also represents a novel and metal-free cross-coupling reaction that leads to ipso-substitution on polycyanoarene via aryl-cyano bond cleavage. In addition, the reaction is a rare example of introducing carbonnucleophile in the photoinduced electron transfer reaction, except that of cyanide ion.
malononitrile) and electron-rich alkenes in the presence of lithium carbonate and a catalytic amount of 9-cyanophenanthrene or redox-type photosensitizers (electron-mediating photosensitizers), through regioselective anti-Markovnikov photochemical polar addition of 1 into electron-rich alkenes. With 2,5-dimethyl-2,4-hexadiene (2g) as an electron-rich alkene, propanedinitrile-incorporated dimer 4g was
Photoinduced three-component coupling reactions of electron deficient alkenes, dienes and active methylene compounds
作者:Hajime Maeda、Hiroshi Takayama、Masahito Segi
DOI:10.1039/c8pp00239h
日期:2018.8
anion serve as electron donors in this process. Based on the results of UV-vis absorption spectroscopy and the calculated ΔG values for single electron transfer (SET), mechanisms are proposed for the coupling reaction involving photoinduced electron transfer (PET) between the electron deficient alkenes and dienes or malononitrile anion via direct excitation of electron deficient alkenes or redox photosensitization