The project described herein involves a computational mechanistic analysis of an intermolecular hydroacylation reaction with an alkene and a β-S-substituted aldehyde. Two products are formed in the reaction, a ketone and an ester, and the calculated reaction pathways that lead to these products begin with the same set of initial steps but diverge at a point midway through the cycle. A key component in the catalysis is the role played by the hemilabile chelating phosphine ligand. Our analysis reveals that the oxygen of the DPEphos ligand participates in hemilabile binding to the metal, this binding allows one of the phosphines to dissociate and thereby open up a coordination site. This stands in contrast to the originally proposed role of the ligand where both phosphines remain coordinated and only the oxygen donor is hemilabile. The associated graphic shows the divergence point where different substrates coordinate to the open coordination site. If the red alkene coordinates, a ketone is ultimately produced. If a second equivalent of blue aldehyde coordinates, an ester is produced. The full, multi-step reaction pathways will be presented.

Divergent mechanistic pathways in a metal-catalyzed hydroacylation reaction

253rd National Meeting (2017)

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