Continuous-flow alcohol protection and deprotection reactions catalyzed by silica-supported sulfonic acid
Berg, Sebastiaan A. van den; Frijns, Raoul A.M. ; Wennekes, Tom ; Zuilhof, Han - \ 2015
Journal of Flow Chemistry 5 (2015)2. - ISSN 2062-249X - p. 95 - 100.
Alcohol protection and deprotection - Catalysis - Continuous flow - Packed bed - Silyl ether
Alcohol protection and deprotection reactions, catalyzed by solid-supported sulfonic acid, have been investigated under continuous-flow conditions. Primary, secondary, benzylic and phenolic alcohols can be protected under these conditions by tetrahydropyranyl and several silyl ether moieties, generating synthetically useful amounts of material in short time. Furthermore, the described setup can be used to deprotect protected alcohols and be used in selective protection reactions. Because the solid-supported acid catalyst is continually reused in a packed-bed approach, workup is greatly simplified and in most cases only solvent removal is necessary, while reaching high turn-over numbers.