Protecting Groups for Thiols Suitable for Suzuki Conditions.
The thiol group is one of the few groups NOT tolerated by the Suzuki reaction. Therefore, a new protective group, the 2-methoxyisobutyryl group, was developed by tuning the electronic/steric properties of the acyl residue. Other thioesters, such as thioacetate, result in a more or less dominant side reaction, which to date has not been described: sulfur-assisted acylation of boronic acids. The reaction pathway for this new reaction is discussed.
Zeysing
B
Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany.
Gosch
C
Terfort
A