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Papers by Daniel Shore
Journal of Organic Chemistry, 2009
Malonic acid half thioesters (MAHTs) and malonic acid half oxyesters (MAHOs) are shown to undergo... more Malonic acid half thioesters (MAHTs) and malonic acid half oxyesters (MAHOs) are shown to undergo decarboxylative nucleophilic addition reactions with ketone and aldehyde electrophiles in the presence of stoichiometric or catalytic quantities of triethylamine at room temperature. The ability to perform these reactions under metal-free conditions has enabled a detailed mechanistic analysis of the reaction pathway leading to the (1)H NMR spectroscopic characterization of a postnucleophilic addition/predecarboxylation intermediate and experimental evidence for a reversible formation of this intermediate followed by an irreversible decarboxylation. Rate constants for each of the bond forming/bond breaking steps in the reaction pathway were also determined, casting light on the differing reactivity between MAHO and MAHT nucleophiles in these processes. Finally, the mechanistic insights gained through these studies have been employed in the development of a new decarboxylative coumarin synthesis.
Organic letters, Jan 26, 2006
New reaction conditions are described that enable the direct arylation of pentafluorobenzene with... more New reaction conditions are described that enable the direct arylation of pentafluorobenzene with sterically encumbered aryl bromides and aryl chlorides. These reactions occur in high yield and under mild conditions. Notably, the reactions can be performed at 80°C in isopropyl acetate with a catalyst generated by the in situ mixing of Pd(OAc) 2 and S-Phos. The enhanced scope of these transformations should further reduce the need to use pentafluorophenylboronic acid in the construction of perfluoroarenes.
Journal of Organic Chemistry, 2009
Malonic acid half thioesters (MAHTs) and malonic acid half oxyesters (MAHOs) are shown to undergo... more Malonic acid half thioesters (MAHTs) and malonic acid half oxyesters (MAHOs) are shown to undergo decarboxylative nucleophilic addition reactions with ketone and aldehyde electrophiles in the presence of stoichiometric or catalytic quantities of triethylamine at room temperature. The ability to perform these reactions under metal-free conditions has enabled a detailed mechanistic analysis of the reaction pathway leading to the (1)H NMR spectroscopic characterization of a postnucleophilic addition/predecarboxylation intermediate and experimental evidence for a reversible formation of this intermediate followed by an irreversible decarboxylation. Rate constants for each of the bond forming/bond breaking steps in the reaction pathway were also determined, casting light on the differing reactivity between MAHO and MAHT nucleophiles in these processes. Finally, the mechanistic insights gained through these studies have been employed in the development of a new decarboxylative coumarin synthesis.
Organic letters, Jan 26, 2006
New reaction conditions are described that enable the direct arylation of pentafluorobenzene with... more New reaction conditions are described that enable the direct arylation of pentafluorobenzene with sterically encumbered aryl bromides and aryl chlorides. These reactions occur in high yield and under mild conditions. Notably, the reactions can be performed at 80°C in isopropyl acetate with a catalyst generated by the in situ mixing of Pd(OAc) 2 and S-Phos. The enhanced scope of these transformations should further reduce the need to use pentafluorophenylboronic acid in the construction of perfluoroarenes.