- Insight into Copper Catalysis: In Situ Formed Nano Cu2O in Suzuki-Miyaura Cross-Coupling of Aryl/Indolyl Boronates
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A ligand-free copper catalyzed Suzuki-Miyaura coupling of 3,5-diiodopyridine with aryl and indole boronates has been explored in good to excellent yields. In situ generation of nano-Cu2O from CuCl2 under the reaction conditions has been discovered for the first time. The generality of the reaction was further demonstrated by the arylation of 5-iodopyrimidine, iodopyridines, iodobenzenes, and diiodobenzenes and resulted in good to moderate yields. Moreover, bisindole alkaloid Scalaridine A has been successfully synthesized in 60% overall yield.
- Ranjani, Ganapathy,Nagarajan, Rajagopal
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supporting information
p. 3974 - 3977
(2017/08/14)
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- Photo-induced Metal-Catalyst-Free Aromatic Finkelstein Reaction
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The facile iodination of aromatic compounds under mild conditions is a great challenge for both organic and medicinal chemistry. Particularly, the synthesis of functionalized aryl iodides by light has long been considered impossible due to their photo-lability, which actually makes aryl iodides popular starting materials in many photo-substitution reactions. Herein, a photo-induced halogen exchange in aryl or vinyl halides has been discovered for the first time. A broad scope of aryl iodides can be prepared in high yields at room temperature under exceptionally mild conditions without any metal or photo-redox catalysts. The presence of a catalytic amount of elemental iodine could promote the reaction significantly.
- Li, Lu,Liu, Wenbo,Zeng, Huiying,Mu, Xiaoyue,Cosa, Gonzalo,Mi, Zetian,Li, Chao-Jun
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supporting information
p. 8328 - 8331
(2015/07/15)
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- Alkali-metal mediated zincation of N-heterocyclic substrates using the lithium zincate complex, (THF)Li(TMP)Zn(tBu)2 and applications in in situ cross coupling reactions
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This study investigates the ability of the mixed-metal reagent [Li(TMP)Zn(tBu)2] 1 to promote direct Zn-H exchange reactions (zincations) of a wide range of N-heterocyclic molecules. The generated metallated intermediates from these reactions are intercepted with I2 and some of them are also employed as precursors in Pd-catalysed Negishi cross-coupling applications. A comparison with recent precedents in metallation chemistry reveals that for some of these heterocycles, 1 allows improved conversions, under milder conditions and in certain cases, even gives unique regioselectivities.
- Blair, Victoria L.,Blakemore, David C.,Hay, Duncan,Hevia, Eva,Pryde, David C.
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supporting information; experimental part
p. 4590 - 4594
(2011/09/30)
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- Deprotonative metalation of substituted benzenes and heteroaromatics using amino/alkyl mixed lithium-zinc combinations
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Different homoleptic and heteroleptic lithium-zinc combinations were prepared, and structural elements obtained on the basis of NMR spectroscopic experiments and DFT calculations. In light of their ability to metalate anisole, pathways were proposed to justify the synergy observed for some mixtures. The best basic mixtures were obtained either by combining ZnCl 2·TMEDA (TMEDA = N,N,N',N'tetramethylethylenediamine) with [Li(tmp)] (tmp = 2,2,6,6-tetramethylpiperidino; 3 equiv) or by replacing one of the tmp in the precedent mixture with an alkyl group. The reactivity of the aromatic lithium zincates supposedly formed was next studied, and proved to be substrate-, base-, and electrophile-dependent. The aromatic lithium zincates were finally involved in palladium-catalyzed cross-coupling reactions with aromatic chlorides and bromides.
- Snegaroff, Katia,Komagawa, Shinsuke,Chevallier, Floris,Gros, Philippe C.,Golhen, Stephane,Roisnel, Thierry,Uchiyama, Masanobu,Mongin, Florence
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experimental part
p. 8191 - 8201
(2010/09/11)
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- Deprotonative zincation of heteroaromatics using ZnI2 and tert-Bu-P4 base
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The direct deprotonative zincation of diazines was accomplished using the combination of ZnI2 and t-Bu-P4 base and unique regioselectivities of zincation were observed.
- Imahori, Tatsushi,Suzawa, Koichi,Kondo, Yoshinori
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scheme or table
p. 1057 - 1060
(2009/06/28)
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- Lithium-mediated zincation of pyrazine, pyridazine, pyrimidine, and quinoxaline
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(Chemical Equation Presented) Deprotonation of pyrazine, pyridazine, pyrimidine, and quinoxaline using an in situ mixture of ZnCl2· TMEDA (0.5 equiv) and LiTMP (1.5 equiv) was studied. Pyrazine and pyrimidine were deprotonated in THF at room te
- Seggio, Anne,Chevallier, Floris,Vaultier, Michel,Mongin, Florence
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p. 6602 - 6605
(2008/02/10)
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- Method for treating arthritis with 6-aryl pyrimidine compounds
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This invention relates to 6-aryl pyrimidine compounds which have now been found to be useful for treatment or prevention of arthritis.
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