Palladium-catalysed synthesis of biaryl phosphines
摘要:
Monodentate, biphenyl-type phosphines have emerged as a powerful class of ligands in homogeneous catalysis. Synthetic methods for these ligands are limited, however. We report that the palladium-catalysed Suzuki coupling of OPR2(o-C6H4X) (R=Ph, t-Bu; X=Br, I) with arylboronic acids affords a variety of biaryl phosphine oxides including those that contain heterocycles. The corresponding phosphines are readily obtained by treatment with HSiCl3. The methodology provides an easy entry to monodentate biaryl and heterobiaryl P<^>X (X=N, O, S) phosphines with diverse steric and electronic properties. (C) 2004 Elsevier Ltd. All rights reserved.
Palladium-catalysed synthesis of biaryl phosphines
摘要:
Monodentate, biphenyl-type phosphines have emerged as a powerful class of ligands in homogeneous catalysis. Synthetic methods for these ligands are limited, however. We report that the palladium-catalysed Suzuki coupling of OPR2(o-C6H4X) (R=Ph, t-Bu; X=Br, I) with arylboronic acids affords a variety of biaryl phosphine oxides including those that contain heterocycles. The corresponding phosphines are readily obtained by treatment with HSiCl3. The methodology provides an easy entry to monodentate biaryl and heterobiaryl P<^>X (X=N, O, S) phosphines with diverse steric and electronic properties. (C) 2004 Elsevier Ltd. All rights reserved.
An effective synthesis of chiral atropoisomeric biaryl phosphine-olefin compounds via palladium-catalyzed enantioselective C-H olefination has been developed for the first time. The reactions are operationally simple, tolerate wide functional groups, and have a good ee value, Notably, P(O)R-2 not only acts as the directing group to direct C-H activation in order to make a useful ligand but also serves to facilitate composition of the product in a useful manner in this transformation.