- Titanium catalyzed one-pot multicomponent coupling reactions for direct access to substituted pyrimidines
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A titanium-catalyzed 3-component coupling reaction can be used to generate tautomers of 1,3-diimines. These diimines produced in situ undergo condensation with amidines in a one-pot procedure to provide substituted pyrimidines. Seventeen examples of pyrimidines are provided using this one-pot, 4-component procedure from simple starting materials. In some cases, catalyst architecture can be tuned to control the regioselectivity of the alkyne addition. Finally, the regioselectivity of amidine addition to unsymmetrical 1,3-diimines is discussed.
- Majumder, Supriyo,Odom, Aaron L.
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experimental part
p. 3152 - 3158
(2010/06/11)
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- Microwave-assisted, efficient and regioselective Pd-catalyzed C-phenylation of halopyrimidines
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We herein report that flash heating microwave irradiation is a helpful tool in the formation of arylpyrimidines from the corresponding halopyrimidines. The palladium-catalyzed cross-coupling reactions of 2,4-di- and 2,4,5-trihalopyrimidines with phenylboronic acid under the above conditions are described. By use of the appropriate catalyst and the adequate halopyrimidine, good regioselectivity can be achieved in the 2-, 4-, or 5-positions of the heterocycle. In addition, we show that this methodology is ameneable for the stepwise preparation of mono-, di-, and triphenylpyrimidines.
- Ceide, Susana Conde,Montalban, Antonio Garrido
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p. 4415 - 4418
(2007/10/03)
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