title: Large-scale green chemical synthesis of adjacent quaternary chiral centers by continuous flow photodecarbonylation of aqueous suspensions of nanocrystalline ketones.
abstract: 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.
authors.affiliation: Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095-1569, United States.
authors.forename: María Guadalupe
authors.initials: MG
authors.lastname: Hernández-Linares
authors.forename: Gabriel
authors.initials: G
authors.lastname: Guerrero-Luna
authors.forename: Salvador
authors.initials: S
authors.lastname: Pérez-Estrada
authors.forename: Martha
authors.initials: M
authors.lastname: Ellison
authors.forename: Maria-Mar
authors.initials: MM
authors.lastname: Ortin
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Garcia-Garibay