Session: Undergraduate Research Posters: Organic Chemistry:

The hydroacylation of alkenes by aldehydes represents an atom-efficient option in the synthesis of ketones. The use of organic initiators such as phenyl glyoxylic acid offers additional opportunities to meet Green Principle goals over metal-based photo-initiators. Photo-initiated hydroacylation is known to suffer from decarbonylation of intermediate acyl radicals resulting in hydroalkylation product formation. In alkyl aldehydes, the stability of alky-radical produced by decarbonylation exacerbates this problem. In a program directed to optimizing the utility of photo-hydroacylation, we investigated common photochemical reaction variables. The presence of oxygen in the reaction atmosphere is a known variable. Using a range of alkyl-aldehydes the data shows a reduction in hydroalkylation when the reactions are nitrogen sparged. Considering the potential for singlet oxygen formation when oxygen is present, we also investigated the influence of reaction wavelength in a range from 365 - 455 nm. Higher wavelengths also show less hydroalkylation. The combination of wavelength and reaction atmosphere offer promise in creating a selective general hydroacylation photoreaction.

Paul Buonora

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