Zirconium-Mediated Selective Synthesis of 1,2,4,5-Tetrasubstituted Benzenes from Two Silyl-Substituted Alkynes and One Internal Alkyne

Li, Shi; Qu, Hongmei; Zhou, Lishan; Kanno, Ken‐ichiro; Guo, Qiaoxia; Shen, Baojian; Takahashi, Tamotsu

doi:10.1021/ol901153p

Cited by 38 publications

(8 citation statements)

References 27 publications

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“…As shown in Scheme 1, 3,6-diiodo-4,5-dialkylphthalic acid dimethyl esters were prepared according to our previous work, 16,18 wherein R 2 was propyl or butyl. The iodine-substituted compounds 1 were reacted with a series of terminal alkynes by Sonogashira coupling to obtain the corresponding 1,4-bis(alkynyl)benzenes 2a–c .…”

Section: Resultsmentioning

confidence: 99%

“…3,6-Diiodo-4,5-dialkylphthalic acid dimethyl esters ( 1 ) were prepared according to our previous work. 16,18…”

Section: Methodsmentioning

confidence: 99%

“…On the basis of our previous works on the zirconocene-mediated cycloaddition of different alkynes, the fully substituted benzenes and 1,2,3,5-tetrasubstituted benzenes were prepared. 16–18 The trimethylsilyl (TMS) groups can be easily substituted with other functional groups 19 and the selective synthesis of 1,4-bis(alkynyl)benzenes from TMS-substituted alkynes by the mediation of Cp 2 Zr(II) species seemed to be an appropriate method. TMS-substituted alkynes were treated with Cp 2 Zr(II) species to afford the corresponding 2,5-bis(trimethylsilyl)zirconacyclopentadienes as single products in high yields with excellent regioselectivity.…”

Section: Introductionmentioning

confidence: 99%

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Zirconocene-mediated selective synthesis of 1,4-bis(alkynyl)benzenes

Zhang

et al. 2020

Journal of Chemical Research

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A series of novel 1,4-bis(alkynyl)benzene derivatives were synthesized from trimethylsilyl-substituted alkynes by the mediation of zirconocene with excellent regioselectivity in high yields. The 3,6-bis(trimethylsilyl)-4,5-dialkylphthalic acid dimethyl esters were prepared by cycloaddition of 2,5-bis(trimethylsilyl)zirconacyclopentadienes to dimethyl acetylenedicarboxylate. After iodination with iodine monochloride, 3,6-diiodo-4,5-dialkylphthalic acid dimethyl esters reacted with terminal alkynes to prepare the corresponding 1,4-bis(alkynyl)benzene derivatives by Sonogashira coupling reactions. After removal of trimethylsilyl, 4,5-dibutyl-3,6-bis(ethynyl)phthalic acid dimethyl ester (compound 3) reacted with 4-iodobenzoic acid ethyl ester and 2-iodothiophene, respectively, to obtain the corresponding products 4a and 4c. Compound 3 can be extended to higher oligomers, which reacted with 1-bromo-4-iodobenzene and phenylacetylene in a stepwise manner under Sonogashira conditions to give the phenylene-ethynylene oligomer 5 in an isolated yield of 85%. The structures of the products were confirmed by 1H NMR spectroscopy, 13C NMR spectroscopy, and MS. The optical properties of the 1,4-bis(alkynyl)benzene derivatives were studied by UV-Vis spectroscopy and fluorescence spectra. The results indicated that some can be developed into potential photovoltaic materials.

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Section: Resultsmentioning

confidence: 99%

“…3,6-Diiodo-4,5-dialkylphthalic acid dimethyl esters ( 1 ) were prepared according to our previous work. 16,18…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Zirconocene-mediated selective synthesis of 1,4-bis(alkynyl)benzenes

Zhang

et al. 2020

Journal of Chemical Research

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“…In our previous studies, zirconacyclopentadienes have been used as intermediates for the synthesis of naphthacene derivatives, multi-substituted benzenes, and 1,2,3,4-tetraalkyl-1,4-diarylbutadienes [20][21][22]. In these studies, zirconacyclopentadienes were formed using silicon-free terminal alkynes and internal alkynes as starting materials.…”

Section: Introductionmentioning

confidence: 99%

Zirconium-Mediated Synthesis of Multi-substituted Dibenzosilole and Benzonaphthosilole Derivatives

Zhang

Chen

et al. 2018

Trans. Tianjin Univ.

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In this study, a new zirconium-mediated cycloaddition for preparing dibenzosilole derivatives was developed using siliconbridged diynes and electron-withdrawing alkynes as starting materials. The preparation of silicon-bridged diynes from 1-bromide-2-iodobenzene, terminal alkynes, and dimethyldichlorosilane was also studied. Unlike in the previous synthesis methods, much higher yields of electron-withdrawing group-substituted dibenzosilole derivatives were obtained. In addition, a new synthesis strategy for preparing benzonaphthosilole derivatives using internal alkynes, 1,4-dibromobenzene, and electron-withdrawing alkynes as starting materials is proposed. Compared with previous methods, alkyl, phenyl, and electron-withdrawing groups can be successfully introduced onto aromatic rings, and the positions of these substituents can be easily controlled. The cycloaddition reactions for dibenzosilole and benzonaphthosilole derivatives are highly efficient one-pot processes, and the raw materials are available and easily prepared. Using these new methods, a series of novel multisubstituted dibenzonsilole and benzonaphthosilole derivatives were obtained effectively.

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“…However, there is lack of reports about the influence of this type of interactions on PL, mainly due to synthetic difficulties in 2D-p-conjugated derivatives obtaining. So far, multi-substituted benzene or naphthalene derivatives containing thiophenyls were prepared by: Stille coupling reactions [20,21] Diels-Alder reaction (with CO-extrusion) [22,23], cycloaddition cyclobutene-1,2-diones [24], cyclotrimerization [25] or via intermolecular [2+2+2] cycloaddition catalyzed by Ru(II)-complexes [26]. Recently, in the literature new synthetic route was reported i.e.…”

Section: Introductionmentioning

confidence: 99%