Aminophosphine ligand

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... 

Other chiral ligands such as BINAP (where BINAP is bis(diarylphosphino)-1,1 binaphthyl) or aminophosphines are also efficient for stereoselective synthesis of chiral-at-metal Ru complexes [39-41]. 

The bidentate phosphine dppe (l,2-bis(diphenylphosphino)ethane) and the aminophosphine eddp (2-aminoethyl-diphenylphosphine) form mixed ligand (N, P, O) complexes such as Co(acac) (edpp)2 and Co(acac)(en)(dppe). A preference for trans N-Co-P and P-Co-P configurations over N-Co-N was found for the bis(edpp) complexes.925... 

This section essentially catalogs some of the newer catalyst systems that have not been considered in the previous sections. A number of the catalysts are certainly derived from more established ones (e.g., use of chelated aminophosphine ligand instead of two monodentate phosphines... 

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... 

Other ligands have been examined to improve the performance of platinum-catalyzed reactions,40 and bicyclic aminophosphines (Scheme 7, G) are a sterically demanding structural class that has been employed to afford very high regioselectivities41... 

Although the vast majority of centrally chiral diphosphine ligands to be employed in enantioselective rhodium-catalyzed hydroborations possess -symmetry, there are a few examples of ( -symmetric diphosphine ligands. Buono prepared bis(aminophosphine) ligands 35-38,81 while Bianchini reported (R, i )-BDPBzP 39 (Figure 5).82... 

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. 

Another ligand, the potential of which has only recently been exploited, is Bo-Phoz (35). This ligand is an aminophosphine as well as a phosphine (see also Section 23.7). It has shown high selectivities and activities with enamides and itaconates [154, 155]. 

Mixed Phosphine-Phosphoramidites and Phosphine-Aminophosphine Ligands... 

Fig. 27.5 Mixed phosphine-phosphoramidites and phosphine-aminophosphine ligands.

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

Scheme 36.11 Parallel synthesis of a library of aminophosphine ligands.

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