Abstract While heating 1, 2, 4, 5-tetramethyl-3, 6-bis (phenylethynyl) benzene, 1, 3, 5- trimethyl-2, 4-bis (phenylethynyl) benzene, and 1, 2, 4, 5-tetramethyl-3-(phenylethynyl) benzene with iodine in DMSO in the absence of oxygen, the triple bonds are oxidized to give the corresponding 1, 2-diketones. In the presence of oxygen, the previously unknown competitive oxidative process causes the cleavage of the aryl—ethynyl bonds so that ...
