- A versatile method for suzuki cross-coupling reactions of nitrogen heterocycles
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(Chemical Equation Presented) A wide-ranging study of Suzuki reactions which use nitrogen-containing heterocycles is described (see scheme; dba = dibenzylideneacetone, Cy = cyclohexyl). This method is highly versatile (a single procedure was used for all substrates, including boronate esters and trifluoroborates), compatible with a variety of unprotected functionalities (e.g., NH2-and OH-substituted substrates), and efficient even with unactivated aryl chlorides.
- Kudo, Noriaki,Perseghini, Mauro,Fu, Gregory C.
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p. 1282 - 1284
(2007/10/03)
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- Palladium-catalyzed cross-coupling reactions of pyridylboronic acids with heteroaryl halides bearing a primary amine group: Synthesis of highly substituted bipyridines and pyrazinopyridines
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(Chemical Equation Presented). A range of halogenated aromatics and heteroaromatics bearing a primary amine group are shown to be suitable substrates for Suzuki cross-coupling reactions with arylboronic acids and pyridylboronic acids under standard conditions, without the need for protection/deprotection steps. New amino-substituted arylpyridines, bipyridines, and pyrazinopyridines have thereby been obtained. Conditions for the efficient syntheses of 2-methoxy-5-pyridylboronic acid 1 and 2-methoxy-3-pyridylboronic acid 2 in ca. 75 g batches have been defined. A 2-fold reaction of 2-amino-5-bromopyrazine with 2,5-dimethoxy-1,4-benzenediboronic acid affords 1,4-dimethoxy-2,5-bis[2-(5-aminopyrazyl)]benzene 31. The X-ray crystal structures of 1 and 31·DMF are reported.
- Thompson, Amy E.,Hughes, Gregory,Batsanov, Andrei S.,Bryce, Martin R.,Parry, Paul R.,Tarbit, Brian
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p. 388 - 390
(2007/10/03)
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