Valentin Afanasievich Koptyug (1931—1997) was a scientist specializing in chemistry, the chairman of the Siberian Branch of the USSR Academy of Sciences and the vice-president of the USSR Academy of Sciences (1980—1997). He founder of the influential research group of organic chemistry and chemoinformatics. He investigated the mechanisms of aromatic compounds reactions and carbonium ion molecular rearrangement. He discovered a number of new isomerization reactions and explained the mechanisms of substitution reactions in the aromatic nucleus. He studied the structure and reactivity of arenonium ions and their analogues.