Hernández-Linares, M. G.; Guerrero-Luna, G.; Pérez-Estrada, S.; Ellison, M.; Ortin, M.-M.; Garcia-Garibay, M. A. ?Large-Scale Green Chemical Synthesis of Adjacent Quaternary Chiral Centers by Continuous Flow Photodecarbonylation of Aqueous Suspensions of Nanocrystalline Ketones? J. Am. Chem. Soc. 2015, 137, 1679-21684, DOI: 10.1021/ja512524j.
To demonstrate the ease of scale-up and synthetic potential of some organic solid state reactions, we report the synthesis, crystallization, and solid state photochemistry of acyclic, homochiral, hexasubstituted (+)-(2R,4S)-2-carbomethoxy-4-cyano-2,4-diphenyl-3-pentanone 1. We demonstrate that solid state photodecarbonylation of (+)-(2R,4S)-1 affords (+)-(2R,3R)-2-carbomethoxy-3-cyano-2,3-diphenyl-butane 2 with two adjacent stereogenic, all-carbon substituted quaternary centers, in quantitative chemical yield and 100% diastereoselectivity and enantiomeric excess. The efficient multigram photodecarbonylation of (+)-(2R,4S)-1 as a nanocrystalline suspension in water using a continuous flow photoreactor shows that the large-scale synthesis of synthetically challenging compounds using photochemical synthesis in the solid state can be executed in a remarkably simple manner.