[Show abstract][Hide abstract] ABSTRACT: Alkylated
terpyridine ligands are an increasingly important component
of catalysis and dyes but are costly because their synthesis is challenging
and often low-yielding. We report an improved method for the Pd/C-catalyzed
dehydrogenative coupling of 4-picoline to form the bi- and terpyridine.
The addition of MnO2 improves the yield of the reaction,
making the reaction useful on a large scale (up to 200 mmol). The
use of Pd(OAc)2 or Pd/C/pivalic acid leads to the selective
formation of bipyridine.
Preview · Article · Oct 2014 · The Journal of Organic Chemistry
[Show abstract][Hide abstract] ABSTRACT: A general protocol for the coupling of haloarenes with a variety of allylic acetates is presented. Strengths of the method are a tolerance for electrophilic (ketone, aldehyde) and acidic (sulfonamide, trifluoroacetamide) substrates and the ability to couple with a variety of substituted allylic acetates. Secondary alkyl bromides can also be allylated under slightly modified conditions, demonstrating the generality of the approach. Finally, the coupling of a reactive vinyl halide could be achieved by the use of a very hindered ligand and more reactive, branched allylic acetates.
No preview · Article · Oct 2012 · The Journal of Organic Chemistry
[Show abstract][Hide abstract] ABSTRACT: The first general method for the reductive dimerization of alkyl halides, alkyl mesylates, alkyl trifluoroacetates, and allylic acetates is reported which proceeds with low catalyst loading (0.5 to 5 mol%), generally high yields (80% ave yield), and good functional-group tolerance.
No preview · Article · Aug 2010 · Chemical Communications