Dedicated to Dr. Valerjans Kauss on the occasion of his 60th birthday
Abstract
2-Methylprenyl (MePre) is an efficient protection for sulfonamides. The acidic cleavage
of this group leads to volatile by-products and the product can be obtained in high
purity without additional purification. MePre group is resistant to Pd/C-catalysed
hydrogenolysis at 1 atm, Suzuki–Miyaura reaction, Ni(0) catalysis conditions and oxidising
reagents such as NIS and DDQ. The prenyl (Pre) group can also be used to protect sulfonamides
in certain cases; however, the substrate scope is limited due to the side product
formation.
Key words
sulfonamides - protecting groups - allylation - cations - cleavage