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91.
Lin-Yan Xu Chun-Yu Liu Shi-Yuan Liu Zhi-Gang Ren David James Young Jian-Ping Lang 《Tetrahedron》2017,73(22):3125-3132
One palladium dichloride adduct of a phosphine-pyridine ligand N-diphenylphosphanyl-2-aminopyridine (L1) [(L1)PdCl2] (1) has been prepared and structurally characterized. Compound 1 can be used as an effective catalyst for the Suzuki-Miyaura cross-coupling reactions of unreactive aryl chlorides with aryl boronic acids, and worked much better than its mono- or bidentate phosphine ligands. The reactions with a wide scope of substrates proceeded to give desired products in good to excellent yields. 相似文献
92.
A new fused heterocyclic derivatives of pyrrole containing acetonitrile or cyanoacetonitrile moiety at 3-position is described by a one-pot multicomponent reaction. The reaction of dimedone, various aniline, aryl glyoxal with malononitrile/ethyl cyanoacetate/methyl cyanoacetate under mild conditions. The present method does not involve any hazardous organic solvents or catalysts. The significant features of this method are readily available starting materials, good yields, and easy purification. 相似文献
93.
Francisco Lara-Ochoa Leticia C. Sandoval-Minero Georgina Espinosa-Pérez 《Tetrahedron letters》2017,58(1):43-45
A new strategy for a large scale synthesis is developed and evaluated by the improvement of the current synthesis for fenleuton, a drug with important applications in leukotriene-mediated inflammatory diseases that acts through inhibition of the 5-lipoxygenase enzyme. 相似文献
94.
Alkoxy substituted MeO-BIPHEP-type diphosphines ligands for asymmetric hydrogenation of aryl ketones
<正>In this paper,a series of optically active MeO-BIPHEP-type ligands,(S)-6,6′-dimethoxy-2,2'-bis(di-p-alkoxyphenylphosphine)- 1,1′-biphenyl were synthesized and used to prepare the ruthenium complex.The effects of para-substituted were observed,the results showed that the ruthenium catalysts[diphosphine RuCl_2 diamine]containing both t-Bu and i-Pr substitutions have better activities and enantioselectivities than the non-substituted ruthenium catalysts in the asymmetric hydrogenation of acetophenone. 相似文献
95.
Yohei Kiyotsuka 《Tetrahedron》2010,66(3):676-6255
Substitution of optically active allylic picolinate, cis R1-CH(OC(O)(2-Py))CHCHR2 (R1=(CH2)2Ph, R2=CH2OTBS), with phenylcopper reagents derived from salt free PhLi (2 equiv) and CuBr·Me2S (2 and 1 equiv, respectively) was highly promoted by MgBr2 (3 equiv), producing anti SN2′ product regio- and stereoselectively. This reagent system was proven to be general with several picolinates (R1, R2: Ph(CH2)2, PMBO(CH2)3, Me, TBSOCH2, PMBOCH2, c-Hex). Furthermore, aryl copper reagents prepared from ArLi, which was in turn prepared by Li-halogen exchange, was proven to be compatible with the substitution in the presence of larger quantity of MgBr2 than that of LiX coproduced by the exchange. Substitution was not interfered with the steric hindrance on aryl coppers (Ar: 2-MeOC6H4, 2,6-(MOMO)2-4-MeC6H2, 2,6-Me2C6H3, etc.). Similarly, stereodefined cis and trans alkenyl, furyl, and thienyl reagents gave the corresponding anti SN2′ products efficiently. 相似文献
96.
Michael Shevlin 《Tetrahedron letters》2010,51(37):4833-156
The use of sulfate additives such as H2SO4 greatly increases the reactivity of palladium catalysts for the cyanation of aryl and heteroaryl chlorides and renders them more robust toward adventitious air. Using this method, a wide variety of aromatic and heteroaromatic nitriles were prepared in high yield. 相似文献
97.
Laksmikanta Adak 《Tetrahedron letters》2010,51(29):3811-3814
Palladium(0) nanoparticles efficiently catalyze aliphatic aldehyde C-H functionalization by aryl halides to produce alkyl-aryl ketones in good yields. A wide range of substituted aryl and hetero-aryl bromides/iodides and open-chain aldehydes of varied chain length participated in this reaction. 相似文献
98.
1-Decanethiol has been found to be an excellent reagent for the deprotection of aryl methyl ethers. This newly developed protocol afforded the corresponding phenols in good to excellent yields. A clear advantage of 1-decanethiol over the more commonly used thiols is the easy extraction of both the deprotecting reagent and the reaction byproduct into the aqueous phase, which allows an essentially odorless work-up. 相似文献
99.
100.
Congde Huo Chougu SunDongcheng Hu Xiaodong JiaXiaolan Xu Zhongli Liu 《Tetrahedron letters》2011,52(51):7008-7010
The reaction of ethyl diazoacetate with aryl imines can be initiated by persistent cation radical salt tris(4-bromophenyl)aminium hexachloroantimonate, giving exclusively cis-aziridine carboxylates. 相似文献