Solid state photodecarbonylation and properties of quaternary ammonium salts of crystalline keto-diacids

ORGN 508

Farnosh Family, ffamily@chem.ucla.edu and Miguel A. Garcia-Garibay, ffamily@chem.ucla.edu. Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E Young Drive East, Los Angeles, CA 90095
We have recently established the photodecarbonylation reaction in quaternary ammonium salts (QAS) of crystalline ketones as an energy efficient process for the synthesis of molecules with adjacent quaternary centers. Eight different amines, both aliphatic and aromatic, were used to form salts of the same parent keto-diacid. Two advantages of this reaction are: (1) a bond is formed between two quaternary carbons in one step with no side products, and (2) it can be done in the solid state avoiding the use of solvents and other reagents, rendering it environmentally benign. The ammonium counterion was found to play a role in the photoreactivity of the keto-diacid, in that the relative rates of reaction were different among the salts. In this study, we explore the solid state properties of the various QAS in order to understand the variations in photoreactivity. We also examine differences in efficiency of reactions in the bulk and nanocrystals.