Fluorination Reactions in Flow
Fluorinated molecules are found in many commercially important products. This is because fluorination can dramatically improve the properties of compounds especially against metabolic degradation in pharmaceutical or in agrochemical applications. However, the introduction of fluorine is not always straightforward and can add considerably to the cost of goods owing to the hazardous and aggressive nature of the reagents used to introduce fluorine or the inherent expense of specific fluorinated building blocks.
We have developed several methods to incorporate fluorine into various substrates using flow micro-reactor devices often using immobilized reagents and scavengers to effect product clean-up and isolation. In particular, fluorination using N,N-diethylaminosuflur trifluoride (DAST), trifluoromethylation (Ruppert’s reagent) and electrophilic fluorination (Selectfluour) in continuous-flow microreactors . Special attention was given to the use of in-line scavenging procedures to avoid exposure to hazardous by-products such as HF .
1. The use of diethylaminosulfur-trifluoride (DAST) for the fluorination in a continuous flow reactor
M. Baumann, I.R. Baxendale, S.V. Ley
Synlett 2008, 14, 2111-2114
2. Development of fluorination methods using continuous-flow microreactors
M. Baumann, I.R. Baxendale, L.J. Martin, S.V. Ley
Tetrahedron 2009, 65, 6611-6625