Chiral Bis(N-sulfonylamino)phosphine- and TADDOL-Phosphite-Oxazoline Ligands: Synthesis and Application in Asymmetric Catalysis
作者:Robert Hilgraf、Andreas Pfaltz
DOI:10.1002/adsc.200404168
日期:2005.1
has been prepared, containing a chiral oxazoline ring and as a second chiral unit a bis(N-sulfonylamino)phosphine group embedded in a diazaphospholidine ring or a cyclic phosphite group derived from TADDOL. These modular ligands are readily synthesized from chiral amino alcohols and chiral 1,2-diamines or TADDOLs. Palladium and iridium complexes derived from these ligands were found to be efficient catalysts
palladium-catalyzed allylicsubstitutions of a wide range of substrate types and nucleophiles using a bidentate ligand composed of oxazoline and chirally flexible biaryl phosphite elements. This unusually wide substrate scope is shown by experimental and theoretical studies of its η3-allyl and η2-olefin complexes not to be a result of configurational interconversion of the biaryl unit, since the ligand
Bis(perfluoroalkyl) Phosphino-Oxazoline: A Modular, Stable, Strongly π-Accepting Ligand for Asymmetric Catalysis
作者:Zongjian Hu、Yuguang Li、Kai Liu、Qilong Shen
DOI:10.1021/jo3011717
日期:2012.9.21
A new class of stable, strongly π-accepting and modular bis(perfluoroalkyl)-phosphine-oxazoline ligands (FOX) as CO mimics was prepared. It was demonstrated that these ligands, when coordinated to palladium catalysts, promote the asymmetric alkylation of monosubstituted allyl substrates with excellent regio- and enantioselectivity. Solid and solution structure analysis of the FOX-ligated Pd-allyl intermediate
The branched, chiral products 1 are formed preferentially in the allylicalkylations in Equation (1) when the Pd catalyst contains the P,N ligand L* or derivatives thereof. The ligands are readily synthesized from commercially available precursors.
Chiral Bis(<i>N</i>-tosylamino)phosphine- and TADDOL-Phosphite-Oxazolines as Ligands in Asymmetric Catalysis
作者:Robert Hilgraf、Andreas Pfaltz
DOI:10.1055/s-1999-2939
日期:1999.11
A series of P,N-ligands containing a chiral oxazoline ring and a chiral bis(N-tosylamino)phosphine group derived from a 1,2-diamine or a chiral cyclic phosphite group derived from TADDOL has been prepared. These compounds proved to be efficient ligands for enantiocontrol of palladium-catalyzed allylic alkylations and iridium-catalyzed hydrogenations of olefins.