87666-64-6Relevant articles and documents
Syntheses and Spectral Properties of several Branched-chain Polyphenyls containing 1,2,3-Trisubstituted Ring(s)
Ozasa, Shigeru,Fujioka, Yasuhiro,Kikutake, Jun-ichiro,Ibuki, Eiichi
, p. 1572 - 1581 (2007/10/02)
Nine polyphenyls, including six new compound, 3'-phenyl-o-quaterphenyl (3), 2,6-diphenyl-m- (4), 2,6-diphenyl-p-terphenyl (5), 2,6,5'-triphenyl-m-terphenyl (6), 2',2''-diphenyl-m-quaterphenyl (8), and 2'-(phenyl-d5)-m-terphenyl (9), were synthesized by the Ullmann coupling reaction of aryl iodide(s) or by the Karash-type coupling reaction of deuterated aryl Grignard reagent with aryl iodide catalyzed by bis(acetylacetonato)-nickel(II).Infrared studies of the polyphenyls showed that the range 730-770 cm-1, generally accepted as the position of the C-H out-of-plane bending bands of phenyl rings, should be widened slightly to 730-781 cm-1.The high frequency bands were found to be correlated closely to the sterically overcrowded structure of terminal rings.Proton magnetic resonance spectral studies indicated that the characteristic spectral features of the polyphenyls containing 1,2,3-trisubstituted ring(s) were fully consistent with their conformational aspects deduced from stereomodels.Ultraviolet spectral data suggeted that the most probable conformation of the highly crowded 3',6''-diphenyl-o-quaterphenyl (1) is one in which the interplanar angles of the pivot bonds between the 1,2,3-trisubstituted ring and three benzene rings are rather smaller than those of the less crowded 2'-phenyl-m-terphenyl (2).Keywords - Ullmann reaction; nickel-complex-catalyzed cross-coupling; quaterphenyl; deuterated quaterphenyl; quinquephenyl; sexiphenyl; polyphenyl; IR; UV; 1H-NMR
Preparation and Conformational Properties of Several 1,8-Diarylnaphthalenes
Ibuki, Eiichi,Ozasa, Shigeru,Fujioka, Yasuhiro,Mizutani, Hiroshi
, p. 845 - 851 (2007/10/02)
Six new 1,8-diarylnaphthalenes, each having closely held parallel aromatic rings, were synthesized by a Kharash-type Grignard cross-coupling of arylmagnesium iodide and 1,8-diiodonaphthalene in the presence of N,N'-bis(1-methyl-3-oxobutylidene)ethylenediaminatonickel(II) as a catalyst.Among them, 1,8-di(1-naphthyl)naphthalene was obtained as cis and trans rotamers, caused by the restricted rotation at the 1,8-position.Interconversion between the rotamers on heating above their melting points was confirmed by differential scanning calorimetry.The proton magnetic resonance spectral studies of the 1,8-diarylnaphthalenes indicated the presence of a face-to-face arrangement of aromatic rings in the peri-position.Two new 8,8'-diaryl-1,1'-binaphthyls, each having two sets of closely held parallel aromatic rings, were isolated as minor coupling products.Trans-trans conformations were proposed for them on the basis of their thermal behavior.Several nickel(II) complexes were found to be effective catalysts for preparative Grignard cross-coupling reaction involving closely crowded geometry.