TADDOL-based ,-bidentate phosphoramidite ligands in palladium-catalyzed asymmetric allylic substitution.

A series of easy-to-prepare and modular chiral ,-bidentate phosphoramidites were synthesized. With respect to Pd(II), these ligands showed the ability to form stable ,-chelate allylic complexes. The structures of the ligands and their complexes were confirmed by 2D NMR spectroscopy and single-crystal X-ray diffraction.

Diamidophosphites from β-hydroxyamides: readily assembled ligands for Pd-catalyzed asymmetric allylic substitution.

Two groups of modular chiral diamidophosphite ligands were easily synthesised from accessible N-Boc-amino alcohols and pseudodipeptides. The reaction of these compounds with [Pd(allyl)Cl] in the presence of AgBF yielded complexes [Pd(allyl)(L)]BF. In addition, metallochelates [Pd(allyl)(L)]BF with (S)-methioninol-based P,S-bidentate ligands were prepared.

Novel P,N-bidentate phosphite ligands in asymmetric catalysis.

Results achieved by the authors in the synthesis of chiral P,N-phosphite ligands are summarized. Three groups of new chiral P,N-phosphites are discussed, namely, ligands derived from 1,1'-bi-2-naphthol, ligands possessing an acyclic phosphorus center, and P*-chiral ligands derived from (S)-2-anilinomethylpyrrolidine. An overview of complexation of the ligands with Rh(I) and Pd(II) precursors is given.