Oxovanadium(V)-Induced Cross-Coupling Reaction between Two Ligands of Organozinc Compounds
作者:Toshikazu Hirao、Takashi Takada、Akiya Ogawa
DOI:10.1021/jo9919106
日期:2000.3.1
Oxovanadium(V) compounds such as VO(OEt)Cl(2) serve as useful oxidants for organozinc compounds, providing the corresponding cross-coupling products derived from two ligands of organozinc compounds. In particular, triorganozincates undergo selective cross-coupling smoothly by the action of oxovanadium(V).
spectral studies of the 1,8-diarylnaphthalenes indicated the presence of a face-to-face arrangement of aromaticrings in the peri-position. Two new 8,8′-diaryl-1,1′-binaphthyls, each having two sets of closely held parallel aromaticrings, 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
六种新的 1,8-二芳基萘,每个都具有紧密的平行芳环,在 N,N'-双(1-甲基)存在下,通过芳基碘化镁和 1,8-二碘萘的 Kharash 型格氏交叉偶联合成。 -3-氧代丁叉基)乙二胺镍(II)作为催化剂。其中,1,8-二(1-萘基)萘以顺式和反式旋转异构体的形式获得,这是由于1,8-位旋转受限。通过差示扫描量热法确认旋转异构体之间在加热至其熔点以上时的相互转化。1,8-二芳基萘的质子磁共振光谱研究表明,在邻位存在芳香环的面对面排列。两个新的 8,8'-二芳基-1,1'-联萘,每个都有两组紧密相连的平行芳环,被分离为次要的偶联产物。根据它们的热行为提出了反式-反式构象。发现几种镍 (II) 配合物是有效的催化剂...
Parent <i>o</i>-Phenylene Oligomers: Synthesis, Conformational Behavior, and Characterization
作者:Sanyo M. Mathew、C. Scott Hartley
DOI:10.1021/ma201866p
日期:2011.11.8
have been reported, most of the basic properties of the parent compounds are unknown. Here we report the synthesis and characterization of the series of unsubstituted o-phenylene oligomers up to the octamer. Through a combination of NMR spectroscopy, including dynamic NMR (EXSY), and computational chemistry, we have found that these compounds adopt compact helical conformations in solution with three
Eight new linear octiphenyls containing two or three kinds of linkage were synthesized by the Ullmann homo-coupling reaction of iodoquaterphenyl. Among them, five compounds were alternatively synthesized by the Kharash-type Grignard cross-coupling of biphenylylmagnesium bromide and diiodoquaterphenyl or of terphenylylmagnesium iodide and diiodoquaterphenyl in the presence of bis (acetylacetonato) nickel (II). Spectral studies proved that the octiphenyls thus prepared displayed highly characteristic infrared, ultraviolet, and nuclear magnetic resonance spectra. Empirical Huckel molecular orbital calculations of the longest wavelength absorption bands of the octiphenyls were also performed. The calculated and observed wavelengths were in rather good agreement, except for the cases of two compounds.
Desulfurization of dibenzothiophene and dibenzothiophene sulfone via Suzuki–Miyaura type reaction: Direct access to o-terphenyls and polyphenyl derivatives
作者:Rubén Gutiérrez-Ordaz、Juventino J. García
DOI:10.1016/j.poly.2018.08.008
日期:2018.11
between the desulfurization of the corresponding substrates via a hydrodesulfurization (HDS) or by a hydrodesulfurative cross-coupling (HDSCC) reaction. Furthermore, in the absence of water sulfur-free poly-phenylic compounds were obtained in good yields as a result of a Suzuki–Miyaura type reaction, being the main product in most of the cases the corresponding o-terphenyl derivative, these products are