Correction of the literature citing monoiodo-8-quinolinols: a critical review / Herman Gershon and Donald D. Clarke Harding Laboratory, the New York Botanical Garde, and Fordham University, Bronx, New York 10458, USA
5-iodo-8-quinolinol, 7-iodo-8-quinolinol, 5-iodo-2-methyl-8-quinolinol, 7-iodo-2-methyl-8- quinolinol
Until 1995, all papers that claimed preparation or further study with monoiodo-8-quinolinol were really working with the 7-iodo isomer. Of the 83 relevant citations 67 dealt with incorrect structural assignments, 13 were critiqued due to errors made in synthesis and interpretation, and 9 had the correct structural assignments. This literature review made the following conclusions apparent. 1. Prototropic forms of 8- quinolinol influence orientation of electrophiles. 2. Under strong acidic conditions, the 5 position is favored. 3. Under mild acidic conditions, mixtures of 5 and 7 substituted compounds are formed. 4. Under basic conditions, the incoming electrophile favors the 7 position. 5. When the phenolic group is etherified or complexed with metals, only 5 substitution takes place, and 7 substitution occurs only after the 5 position is filled. 6. NXS is generally a superior halogenating agent than elemental halogen. 7. In order to avoid rearrangements, the more electronegative group should be put into the desired position followed by the less electronegative substituent
Gershon, Herman; Clarke, Donald Dudley PhD; and Clarke, Donald Dudley PhD, "Correction of the literature citing monoiodo-8-quinolinols: a critical review / Herman Gershon and Donald D. Clarke Harding Laboratory, the New York Botanical Garde, and Fordham University, Bronx, New York 10458, USA" (2005). Chemistry Faculty Publications. 10.