Aminophosphine/phosphinite ligands

Several efficient amidophosphine- and aminophosphine-phosphinite ligands have been reported by Agbossou and Carpentier.148,148a 148g Amidophosphine-phosphinite ligands (.9)-Cy.Cy-oxoProNOP and (.V)-Cp,Cp-oxoProNOP... 

A large number of aminophosphine phosphinite ligands was used in the preparation of enantioselective... 

Mixed phosphorus compounds, bearing at least two different tervalent phosphorus moieties have been developed and have found several applications in catalysis. Iri li described the synthesis of aminophosphine-phosphinite ligands 149 and 150, from the commercially available 3-piperidinemethanol and 3-(methylamino) pro-pan-l-ol. Their palladium and platinum complexes 151 and 152, containing metallocyclic rings, were obtained as air-stable compounds with high yields, and characterized by P, and NMR spectroscopy, FTIR spectroscopy and X-ray crystallography. The Pd complexes were effective catalysts on Suzuki-Miyaura cross-coupling reactions of various aryl chlorides and atyl bromides with phe-nylboronic acid. 

Agbossou E., Carpentier J. E. Hapiot E., Suisse I., Mortreux A. The Aminophos-phine-Phosphinites and Related Ligands Synthesis, Coordination Chemistry and Enantioselective Catalysis Coord. Chem. Rev. 1998 I78-I80 1615-1645 Keywords stereoselective Diels-Alder reaction catalysts, aminophosphine-phosphinites, enantioselective catalysts... 

If Q-symmetric ligands are employed in asymmetric hydrogenation instead of the corresponding C2-symmetric ligands, there coexist principally four stereoiso-meric substrate complexes, namely two pairs of each diastereomeric substrate complex. Furthermore, it has been shown that, for particular catalytic systems, intramolecular exchange processes between the diastereomeric substrate complexes should in principle be taken into account [57]. Finally, the possibility of non-estab-hshed pre-equilibria must be considered [58]. The consideration of four intermediates, with possible intramolecular equilibria and disturbed pre-equihbria, results in the reaction sequence shown in Scheme 10.3. This is an example of the asymmetric hydrogenation of dimethyl itaconate with a Rh-complex, which contains a Q-symmetrical aminophosphine phosphinite as the chiral ligand. 

Scheme 33.4 One-step synthesis of aminophosphine phosphinite bidentate ligands.

Cyclic chiral aminophosphine and phosphinite ligands in enantioselective catalysis 03CCR(242)145. 

Chiral ligands containing tervalent phosphorus acid derivatives as coordination sites continue to be explored for asymmetric metal catalysed reactions. New examples this year include the phosphite (119) and stereoisomers, the phosphites (120), 2 the diphosphinite TADDOP (121), the diphosphites (122) containing crown ethers, the aminophosphine-phosphinites AMPP s (123) and... 

Other similar phosphorus ligands on solid supports and screened them in the Heck reaction.Starting from supported amino alcohols, representative members of five different families of phosphine and phosphinite ligands were synthesised /3-aminophosphines 73, A, /3-diphosphinoamines 74, a,/3-diphosphinoamines 75, /3-aminophosphi-nites 76, and A -phosphino-/3-aminophosphinites 77. Following their complexation with Pd(OAc)2, the ligands were screened in the Heck reaction and led to the identification of two lead ligands for future studies. 

Aminophosphine phosphinite (AMPP) ligands constitute an important class of non-C2 diphosphorus ligands. Some of them are prepared from ephedrine and therefore the Juge-Stephan method constitutes an ideal procedure for the synthesis of P-stereogenic AMPP ligands (Scheme 4.30). ... 

The Aminophosphine-Phosphinites and Related Ligands Synthesis, Coordination Chemistry and Enantioselective Catalysis. 

Also, aminophosphine-phosphinites 1 (AMPPs), originally developed as ligands for asymmetric hydrogenation by the Lyon group of Agbossou-Niedercorn and Mortreux [47, 48], have been tested in asymmetric hydroformylation with a tin-free Pt catalyst (Pigure 1.13). 

Certain chiral phosphinite or aminophosphine ligands are also useful for amino acid synthesis. Hydrogenation with a CYCPHOS-Rh complex occurs rapidly to produce high optical yields. The efficacy of this reaction is ascribed to the flexibility of the ligand, which speeds the reaction and gives a fixed chelate ring conformation (26). 

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