- Ligand-Free Iridium-Catalyzed Dehydrogenative ortho C?H Borylation of Benzyl-2-Pyridines at Room Temperature
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A convenient and ligand-free iridium-catalyzed dehydrogenative ortho C?H borylation of benzyl-2-pyridines has been developed. The reaction proceeds smoothly at room temperature using pinacolborane as a borylating reagent in the presence of catalytic amount of [IrOMe(COD)]2. The reaction is compatible with many functional groups, providing a vast array of ortho borylated products in moderate to excellent yields with excellent selectivities. (Figure presented.).
- Yang, Yuhuan,Gao, Qian,Xu, Senmiao
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supporting information
p. 858 - 862
(2019/01/04)
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- [1,2]-Wittig rearrangement of aromatic heterocycles
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Anionic rearrangement of diverse heteroaryl ethers is reported. In many cases, directed metallation followed by formal [1,2]-Wittig rearrangement provides heteroaryl carbinols in good yield.
- Yang, Jingyue,Wangweerawong, Apiwat,Dudley, Gregory B.
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scheme or table
p. 1603 - 1606
(2012/08/29)
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- Chiral organomagnesiates as dual reagents for bromine-magnesium exchange of 2-bromopyridine and access to chiral α-substituted 2-pyridylcarbinols
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New chiral ligand containing butyl and dibutylmagnesiates have been prepared from a range of ligands and their reactivity studied. The reagents were generally efficient in promoting the clean bromine-magnesium exchange of 2-bromopyridine at room temperature and the subsequent reaction with aldehydes to afford α-substituted 2-pyridylcarbinols in good yields. (R,R)-TADDOLate proved to be the best ligand, leading to acceptable to good enantioselectivities. To the best of our knowledge this is the first example of an organomagnesiate-induced halogen-metal exchange followed by an enantioselective addition.
- Catel, Delphine,Chevallier, Floris,Mongin, Florence,Gros, Philippe C.
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supporting information; experimental part
p. 53 - 57
(2012/02/06)
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- Pyridylmagnesiates: Generation by bromine-metal exchange and enantioselective addition to aldehydes
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Butyl and dibutylmagnesiates incorporating chiral ligands have been prepared and their reactivity studied. The reagents were efficient to promote the clean bromine-magnesium exchange of azinyl bromides at room temperature and subsequent reaction with aldehydes affording pyridylcarbinols. (R,R)-TADDOL-based dibutylmagnesiate was the best reagent leading to acceptable to good enantioselectivities, depending on the substrate and on the aldehyde substitution. This is the first example of enantioselective addition of in situ generated pyridylmagnesiate to carbonyl electrophiles.
- Catel, Delphine,Payen, Olivier,Chevallier, Floris,Mongin, Florence,Gros, Philippe C.
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experimental part
p. 4018 - 4028
(2012/07/28)
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- Highly flexible O,O′,N ligands and their Fe, Ni, Cu and Zn complexes
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Three new chiral ligands bearing an O,O′,N donor set (O methoxyOhydroxyNpyridine) were synthesised and coordinated to FeIII, FeII, NiII, Cu II and ZnII to yield complexes with the general formula [M(OON)Clx]y. While the pyridine N and the hydroxy O atoms coordinate strongly to all applied metal ions, the methoxy donor seems not to be involved in coordination, although some evidence for a weak interaction between OMe and the ZnII were found in NMR spectra. In the bidentate O′,N coordination mode the new ligands exhibit several coordination geometries as analysed in the solid compounds by XRD, EXAFS and EPR and in solution by UV-Vis absorption, cyclic voltammetry, EXAFS, EPR or NMR spectroscopy.
- Butsch, Katharina,Klein, Axel,Bauer, Matthias
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experimental part
p. 350 - 358
(2011/09/16)
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- [1,2]-Anionic rearrangement of 2-benzyloxypyridine and related pyridyl ethers
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(Chemical Equation Presented) An anionic rearrangement of 2-benzyloxypyridine is described. Pyridine-directed metalation of the benzylic carbon leads to 1,2-migration of pyridine via a postulated associative mechanism (addition/elimination). Several aryl pyridyl carbinols were obtained in high yields. A formal synthesis of carbinoxamine, an antihistamine drug used for the treatment of seasonal allergies and hay fever, emerges from this methodology.
- Yang, Jingyue,Dudley, Gregory B.
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supporting information; experimental part
p. 7998 - 8000
(2010/03/01)
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