2-Substituted pyridine, quinoline, isoquinoline, bipyridine, and 1,10-phenanthroline analogues of benzylic acetates undergo SmI 2 -promoted coupling with aldehydes and ketones to afford (2-hydroxyalkyl)heteroaromatics.

SmI(2) serves as an effective promoter for the coupling of 1,10-phenanthroline with an epoxide to generate a new class of chiral, functionalized ligands that readily form complexes with metals. Structural studies of the resulting phenanthroline derivative and two of its metal complexes are reported.

1,10-Phenanthroline reacts with aldehydes and ketones in the presence of samarium diiodide to produce 2-(1-hydroxyalkyl)-1,10-phenanthrolines. The hydroxyalkyl substituent can be functionalized in numerous ways or removed to permit further ligand variation. The carbonyl coupling reaction can also be repeated to provide 2,9-disubstituted phenanthrolines. Taken together, these operations provide ready access to a large number of phenanthroline derivatives to serve as ligand libraries for catalyst exploration.

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Fused pyridine derivativesFused pyridine derivatives R 0450 Samarium-Promoted Coupling of 1,10-Phenanthroline with Carbonyl Compounds for Synthesis of New Ligands. -A methodology for the synthesis of a wide variety of phenanthroline ligands is now available. 1,10-Phenanthroline (I) readily undergoes coupling with aliphatic carbonyl compounds (II) or (VIII) in the presence of SmI2 to afford 2-(hydroxyalkyl)-substituted phenanthrolines in moderate to good yields. The reaction outcome strongly depends on the order of addition of reagents, since aliphatic aldehydes (VIII) only undergo reaction if they are mixed with phenanthroline (I) prior to addition of SmI2. Aromatic carbonyl compounds are not reactive under the presented reaction conditions. Further functionalization of the side chain is achieved by O-alkylation or O-acylation and subsequent deoxygenation reactions. -(WEITGENANT, J. A.; MORTISON, J. D.; O'NEILL, D. J.; MOWERY, B.; PURANEN, A.; HELQUIST*, P.; J.

The reaction affords a variety of synthetically useful (2-hydroxyalkyl)heteroaromatics mostly in moderate yields. Substrates (X) are found to be unreactive. -(WEITGENANT, J. A.; MORTISON, J. D.; HELQUIST*, P.; Org. Lett. 7 (2005) 17, 3609-3612; Dep. Chem. Biochem., Univ. Notre Dame, Notre Dame, IN 46556, USA; Eng.) -R. Steudel 52-125