Photo-inducedelectrontransfer reactions of tetraalkylsilanes, -germanes, and -stannanes with aromaticnitriles afforded alkylated products. The mechanism was investigated by use of a radical clock.
Irradiation of 1-aryl-2,2-dicyanoethenes and tetraalkylstannanes in propionitrile in the presence of phenanthrene afforded regioselectively 1-alkyl-1-aryl-2,2-dicyanoethanes in good yields.
2,6-diphenylpyrylium and 2,6-di-t-butylpyrylium perchlorates are easily converted into a number of the corresponding 4-alkyl derivatives by photochemical reaction with tetraalkylstannanes, in MeCN at room temperature. The mechanism of the process is discussed.