Ylide-Functionalized Phosphines: Strong Donor Ligands for Homogeneous Catalysis

Ylide Ligands

The use of ylides of P, N, As or S as ligands toward transition metals is still a very active research area in organometallic chemistry. This fact is mainly due to the nucleophilic character of the ylides and to their particular bonding properties and coordination modes. They can behave as monodentate or bidentate –chelate or bridging– species, they can be used as chiral auxiliary reagents, the...

Homogeneous Catalysis Homogeneous Catalysis

Cyclic decapeptide gramicidin S derivatives containing phosphines: novel ligands for asymmetric catalysis.

The cyclic peptide gramicidin S was used as a rigid template to provide novel peptide-based bisphosphine ligands for transition metal catalysis. Two bisphosphine-coordinated Rh(I) complexes allowed asymmetric hydrogenation with 10-52% ee and the corresponding Pd(II) analogues catalysed asymmetric allylic alkylation with 13-15% ee.

Chiral allene-containing phosphines in asymmetric catalysis.

We demonstrate that allenes, chiral 1,2-dienes, appended with basic functionality can serve as ligands for transition metals. We describe an allene-containing bisphosphine that, when coordinated to Rh(I), promotes the asymmetric addition of arylboronic acids to α-keto esters with high enantioselectivity. Solution and solid-state structural analysis reveals that one olefin of the allene can coor...

Proton sponge phosphines: electrospray-active ligands.

Attachment of a proton sponge to a phosphine ligand renders neutral complexes of the ligand highly amenable to analysis by electrospray ionisation mass spectrometry (ESI-MS). The ligand 1,8-bis(dimethylamino)naphthyldiphenylphosphine (3) is extremely efficient and highly selective in forming exclusively [M + H]+ ions, which may be detected at very low concentration. Ionisation efficiency of 3 i...