370571-19-0Relevant articles and documents
Regioselective syntheses of 2,3-substituted pyridines by orthogonal cross-coupling strategies
Koley, Moumita,Wimmer, Laurin,Schnuerch, Michael,Mihovilovic, Marko D.
supporting information; experimental part, p. 1972 - 1979 (2011/04/27)
2-Aryl/alkylamino-3-aryl I and 3-aryl/alkylamino-2-aryl pyridines II, as important potentially bioactive compounds, were synthesized by applying orthogonal cross-coupling strategies. Combinations of the Suzuki-Miyaura, Liebeskind-Srogl, and Buchwald-Hartwig protocols gave access to the title compounds in a straightforward and operationally simple manner. Full control over the regioselectivity at the 2- and 3-positions was achieved by using 2,3-dichloropyridine or 3-iodo-2-(methylthio)pyridine as simple, commercially available starting materials. Within this contribution, efficient and high yielding conditions were developed for the Suzuki-Miyaura cross-coupling reaction of 2-substituted 3-chloropyridines, a transformation formerly underrepresented in the literature. For the synthesis of 3-alkyl/arylamino-2- aryl pyridines, the stability of the methylthio group was exploited under Pd-catalysis in the absence of a copper source. This even enabled the development of an operationally highly facile (semi)-one-pot protocol to access the aforementioned compound class that avoided one purification step. A series of products I and II was prepared by using the developed protocols with excellent regioselectivity and good yields. Copyright
