title: Batch versus flow photochemistry: a revealing comparison of yield and productivity.
abstract: The use of flow photochemistry and its apparent superiority over batch has been reported by a number of groups in recent years. To rigorously determine whether flow does indeed have an advantage over batch, a broad range of synthetic photochemical transformations were optimized in both reactor modes and their yields and productivities compared. Surprisingly, yields were essentially identical in all comparative cases. Even more revealing was the observation that the productivity of flow reactors varied very little to that of their batch counterparts when the key reaction parameters were matched. Those with a single layer of fluorinated ethylene propylene (FEP) had an average productivity 20% lower than that of batch, whereas three-layer reactors were 20% more productive. Finally, the utility of flow chemistry was demonstrated in the scale-up of the ring-opening reaction of a potentially explosive [1.1.1] propellane with butane-2,3-dione.
authors.affiliation: School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS (UK).
authors.forename: Luke D
authors.initials: LD
authors.lastname: Elliott
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Knowles
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Koovits
authors.forename: Katie G
authors.initials: KG
authors.lastname: Maskill
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ralph
authors.forename: Guillaume
authors.initials: G
authors.lastname: Lejeune
authors.forename: Lee J
authors.initials: LJ
authors.lastname: Edwards
authors.forename: Richard I
authors.initials: RI
authors.lastname: Robinson
authors.forename: Ian R
authors.initials: IR
authors.lastname: Clemens
authors.forename: Brian
authors.initials: B
authors.lastname: Cox
authors.forename: David D
authors.initials: DD
authors.lastname: Pascoe
authors.forename: Guido
authors.initials: G
authors.lastname: Koch
authors.forename: Martin
authors.initials: M
authors.lastname: Eberle
authors.forename: Malcolm B
authors.initials: MB
authors.lastname: Berry
authors.forename: Kevin I
authors.initials: KI
authors.lastname: Booker-Milburn
mesh_terms: D061565:Cycloaddition Reaction / Q000191:economics / Q000295:instrumentation*; D004867:Equipment Design; D055668:Photochemical Processes; D010777:Photochemistry / Q000191:economics / Q000295:instrumentation*; D011138:Polytetrafluoroethylene / Q000031:analogs & derivatives / Q000737:chemistry; D014466:Ultraviolet Rays; D005465:Fluorocarbon Polymers
chemical_list: D011138:Polytetrafluoroethylene; C096305:fluorinated ethylene propylene; D005465:Fluorocarbon Polymers
keywords: batch reactors; cycloaddition; flow photochemistry; rearrangement; scale-up