Reactions of 5,6-Dilithioacenaphthene-N,N,N',N'-Tetramethyl-1,2-ethanediamine Complex with α-Diketones. II. Competitive Oxophilic and Carbophilic Additions and Redox Reactions

Article abstract of DOI:10.1246/bcsj.54.3026

The reaction of the title complex (3) with benzil did not give the 1:1 cyclic addition product expected, but gave 5,6-dibenzoylacenaphthene, 5-(1-hydroxy-2-oxo-1,2-diphenylethyl)-6-(2-oxo-1,2-diphenylethoxy)acenaphthene (5), 5-benzoyl-6-(1-hydroxy-2-oxo-1,2-diphenylethyl)acenaphthene, benzoin, and benzilic acid.Compound 5 suggests a new type of oxophilic addition accompanied by a carbophilic addition.The reaction of 3 with 9,10-phenanthrequinone in a 1:1 molar ratio gave both the oxidative homo-coupling product of 3, 1,2,7,8-tetrahydrodicyclopentaperylene,and the hydroquinone dianion, which was converted into 9,10-diacetoxyphenanthrene on acetolysis.The differences in the reaction modes between 3 and α-diketones can basically be understood in terms of the redox potentials and the steric factors of the α-diketones.