Benzil diimines

Tetraphenyl-imidazole 3-oxide 256 (R, R1, R2, R3 = Ph) upon irradiation in methanol solution isomerized to give (Z,Z)-benzil diimine (1979AJC2059). 

Eormation of benzil diimines by MW-assisted solvent-free reaction of benzil with aromatic amines on an alumina surface for 4 min has recently been reported to afford 1,2,3,4-tetraaryl-l,4-diaza-l,3-butadienes in good yields [79]. 

Diaryl-5,6-dihydropyrazines 194 are analogous to benzil dianils311 and are reduced in aqueous solution in an analogous way a diimine-enediamine is analogous to a dione-enediol, and the products from 194 are the expected 2,3-diaryl-l,4,5,6-tetrahydropyrazines 195310 [Eq. (114)]. 

The diimines (38) and (39) formed by the condensation of benzil with en or 1,2-diaminobenzene, respectively, have been shown to form the tetrahedral complexes [CdL].352... 

Cz+diimine macrocycle compounds are formed by template condensations of an a-diketone (usually 2,3-butanedione or benzil), 2 + 2 with diamines, e.g., (34), or 1 +1 with tetraamines, e.g., (35) (Scheme 10). The resulting flat macrocycle cations form many stacked compounds, often with flat metal ion-containing anions, which exhibit spin coupling. The imine groups for the Ni11 compounds are reduced with NaBH4 and one of each cz+diimine function for the Co111 compounds by hypophosphorous acid.44... 

The template condensation of a-diketones with 1,3-propanediamine in the presence of divalent iron, cobalt, nickel, or copper leads to 14-membered-ring macrocyclic complexes containing two a-diimines. A number of complexes of this class, derived from 2,3-butanedione,1-3 1-phenyl-1,2-propanedione,4,5 benzil,6 and substituted benzils,5 have been prepared. Preparation of the Ni(II)... 

Cycloadditions of monoalkoxy- or monoaminosilylenes were observed also by cothermolyses of Mc2Si2X4 (X = OMe, NMe2) with various conjugated 1-mono- and 1,4-diheterodienes. Iminoketones, diimines and 0t,a -dipyridyl, also benzil or 3,5-di-/ert-butyl-o-benzoquinone in low yields, gave [l+4]-cycloaddition products. Unsaturated ketones or imines furnished double-bond isomers, oxa- or azasilacyclopent-3-enes and -4-enes (Scheme 2). The 4-enes are usually the main... 

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