products having many potential synthetic uses. Among these
products are pyridine and quinoline systems that are of
interest in the natural products and pharmaceutical areas9
and as ligands in metal coordination chemistry.10
4-(1-acetoxyalkyl)pyridines are also cleaved when they are
treated with SmI2.13h,l Consistent with this precedent, we
observed that when 2-(1-acetoxypropyl)phenanthroline (1)
is treated with SmI2, the acetate functionality is reductively
cleaved yielding 2-propylphenanthroline (2) (Scheme 1).
One of the most versatile reagents for effecting a vast range
of reductive transformations is samarium diiodide.11 In its
role as a single electron-transfer agent, SmI2 has been
employed in many different types of transformations, includ-
ing couplings,12 cleavages,13 and cyclizations.11i,12b,14
Scheme 1. SmI2 Cleavage and Addition Reactions of a
1,10-Phenanthroline Derivative
Cleavages of suitably activated alkoxy groups are well-
known, and Kato and co-workers have shown that 2- and
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However, when the same acetate 1 is treated with SmI2 in
the presence of a ketone, we have found that 1 undergoes a
reductive coupling to give alcohol 3.
Following this observation, we wished to perform a more
thorough study to test the scope and limitations of this
reductive coupling. We obtained the required substrates by
either of two approaches (Scheme 2). In the simplest cases,
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Scheme 2. Synthesis of Heterocyclic Acetates
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