Polyglycerol as a high-loading support for boronic acids with application in solution-phase Suzuki cross-couplings.
In this paper, we describe the usage of a soluble high-loading polyglycerol support for functionalized boronic acids without further linker design. The quantitatively formed polyglycerol boron esters were subsequently employed in homogeneous Suzuki cross-coupling reactions to give high yields (84-91%) of functional biaryls with minimal amounts of the Pd catalyst (0.2 mol %). In situ precipitation and ultrafiltration were used as simple and effective purification protocols. Furthermore, the reaction conditions were optimized by the choice of the solvent and the catalyst.
Hebel
André
A
Freiburger Materialforschungszentrum, Universität Freiburg, Stefan-Meier-Strasse 21, 79104 Freiburg, Germany.
Haag
Rainer
R