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21.
Tarun Kanti Pradhan 《Tetrahedron letters》2005,46(9):1493-1495
One-pot syntheses of (3-hydroxybenzo[b]thiophen-2-yl) aryl methanones from ortho-methylsulfanylaryl N,N-diethyl amides and of 1-(3-hydroxybenzo[b]thiophen-2-yl)ethanone and 1-(3-hydroxybenzo[b]thiophen-2-yl)propan-1-one via an anionic ortho-Fries rearrangement are described. The hydroxy ketones were used as key intermediates in the synthesis of benzothienopyranones. 相似文献
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Adding a Structural Context to the Deprotometalation and Trans‐Metal Trapping Chemistry of Phenyl‐Substituted Benzotriazole 下载免费PDF全文
Dr. M. Ángeles Fuentes Dr. Alan R. Kennedy Prof. Robert E. Mulvey Dr. John A. Parkinson Dr. Toni Rantanen Dr. Stuart D. Robertson Prof. Victor Snieckus 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(42):14812-14822
Organometallic bases are becoming increasingly complex, because mixing components can lead to bases superior to single‐component bases. To better understand this superiority, it is useful to study metalated intermediate structures prior to quenching. This study is on 1‐phenyl‐1H‐benzotriazole, which was previously deprotonated by an in situ ZnCl2 ? TMEDA/LiTMP (TMEDA=N,N,N′,N′‐tetramethylethylenediamine; TMP=2,2,6,6‐tetramethylpiperidide) mixture and then iodinated. Herein, reaction with LiTMP exposes the deficiency of the single‐component base as the crystalline product obtained was [{4‐R‐1‐(2‐lithiophenyl)‐1H‐benzotriazole ? 3THF}2], [R=2‐C6H4(Ph)NLi], in which ring opening of benzotriazole and N2 extrusion had occurred. Supporting lithiation by adding iBu2Al(TMP) induces trans‐metal trapping, in which C?Li bonds transform into C?Al bonds to stabilise the metalated intermediate. X‐ray diffraction studies revealed homodimeric [(4‐R′‐1‐phenyl‐1H‐benzotriazole)2], [R′=(iBu)2Al(μ‐TMP)Li], and its heterodimeric isomer [(4‐R′‐1‐phenyl‐1H‐benzotriazole){2‐R′‐1‐phenyl‐1H‐benzotriazole}], whose structure and slow conformational dynamics were probed by solution NMR spectroscopy. 相似文献
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《化学:亚洲杂志》2017,12(8):853-859
We have synthesized and fully characterized a photochromic zinc complex with a terphenylthiazole‐based ligand with a salen‐like cavity. The solution stability of the complex was found to be greatly dependent on the state of the photochromic ligand and an interesting photo‐triggered release and uptake of zinc ions was found as well as monitored by its fluorescence. The contrasting stability difference of the zinc complex between its two isomeric states was rationalized by DFT calculations. 相似文献
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Various indane and cyclobuta[a]indene derivatives were synthesized by palladium-catalyzed cyclization of homoallylic alcohol derivatives prepared from Baylis-Hillman adducts. Especially, cyclobuta[a]indene derivative was synthesized stereoselectively by palladium-catalyzed 5-exo-trig/4-exo-trig cascade cyclization, albeit in moderate yield. The Z isomer was formed exclusively in the presence of Et3N by usual Heck-type carbopalladation process while E isomer with Cs2CO3 most likely by a concerted metalation/deprotonation (CMD) process. 相似文献
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