- Pincer thioamide and pincer thioimide palladium complexes catalyze highly efficient negishi coupling of primary and secondary alkyl zinc reagents at room temperature
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Pincer thioamide PdII complex 2 was prepared, and its reaction with cyclohexylzinc chloride yielded novel pincer thioimide PdII complex 3 besides Pd0 species. The structures of complexes 2 and 3 were confirmed by X-ray ana
- Wang, Haibo,Liu, Jing,Deng, Yi,Min, Tianyin,Yu, Ganxiang,Wu, Xiaojun,Yang, Zhen,Lei, Aiwen
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supporting information; experimental part
p. 1499 - 1507
(2009/08/07)
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- An electron-deficient diene as ligand for palladium-catalyzed cross-coupling reactions: An efficient alkylation of aryl iodides by primary and secondary alkylzinc reagents
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An electron-deficient diene, L1, was found to be an effective ligand in facilitating palladium-catalyzed Negishi couplings involving primary and secondary alkylzinc reagents. The reactions took place readily at 60 °C in THF with 5 mol% of a catalyst generated in situ from bis(acetonitrile) palladium dichloride [PdCl2(MeCN)2] and L1, and functional groups such as chloro, bromo, etc. attached to phenyl ring as well as β-H atoms adjacent to the reaction site were well tolerated. The problematic isomerizations in secondary alkyzinc reagents involved in the reactions reported in the literature were also observed in our system when isopropylzinc chloride was employed alone as the nucleophile. However, the isomerization was significantly suppressed when i-Pr2Zn was utilized in the presence of L1.
- Liu, Qiang,Duan, Hui,Luo, Xiancai,Tang, Yang,Li, Gang,Huang, Rong,Lei, Aiwen
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supporting information; experimental part
p. 1349 - 1354
(2009/05/30)
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- Effective Pd-nanoparticle (PdNP)-catalyzed negishi coupling involving alkylzinc reagents at room temperature
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(Chemical Equation Presented) Pd(OAc)2 is an efficient catalyst precursor for Negishi coupling in the presence of Bu4NBr. Secondary and primary alkylzinc reagents with β-H and arylzinc reagents all reacted with aryl iodides at temper
- Liu, Jing,Deng, Yi,Wang, Haibo,Zhang, Hua,Yu, Ganxiang,Wu, Bingbin,Zhang, Heng,Li, Qiang,Marder, Todd B.,Yang, Zhen,Lei, Aiwen
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supporting information; experimental part
p. 2661 - 2664
(2009/05/27)
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- Superior effect of a π-acceptor ligand (phosphine-electron-deficient olefin ligand) in the Negishi coupling involving alkylzinc reagents
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(Chemical Equation Presented) Palladium-catalyzed Negishi cross-coupling involving primary and secondary alkyls, even in the presence of β-H, can be achieved at ambient temperature using chelating ligands containing a phosphine and an electron-deficient olefin. The superior effects of the ligands were shown not only in the desired cross-coupling product yields but also in the fast reaction at mild conditions. This reaction has been also scaled up to 50 g in 0.005 mol % catalyst (20,000 TONs) at room temperature.
- Luo, Xiancai,Zhang, Heng,Duan, Hui,Liu, Qiang,Zhu, Lizheng,Zhang, Tony,Lei, Aiwen
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p. 4571 - 4574
(2008/03/12)
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- The Effects of Stereochemistry of the Bridging Atoms in o-Substituted Arylbenzoic Acids on Root Antigravitropism
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Compounds in which an aryl or heteroaryl ring is linked to the ortho position of a benzoic acid moiety by a bridging group of up to four atoms are shown to inhibit the gravitropic response of cress seedling roots between 1E-5 and 1E-8 M.No significant difference in inhibitory activity is observed between compounds containing up to four saturated or two partially unsaturated bridging atoms, although analogues containing three or four partially unsaturated bridging atoms are one to two orders of magnitude more active.Compounds in which the aryl nuclei are fused together are shown to be inactive at the highest concentration tested.The results have been interpreted in terms of the aryl groups in the molecule interacting with a hypothetical receptor site, with the bridging atoms acting as a more or less flexible coupling to facilitate such interaction.
- Teitei, Tsutomu
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p. 1461 - 1466
(2007/10/02)
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