71941-98-5Relevant articles and documents
Facile phosphite to phosphonate rearrangement of a trialkanolamine-derived triphosphite promoted by triethylaluminum
Shum, Sai P.,King III, Roswell E.,Kuell, Christopher,Rodebaugh, Ronald K.,DeBellis, Anthony D.,Pastor, Stephen D.
, p. 2611 - 2623 (2007)
A facile room temperature rearrangement of a trialkanolamine-derived triphosphite, 1, to the monophosphonate 5 promoted by three equivalents of triethylaluminum is described. The diphosphonate 6 was prepared by the addition of three equivalents of triethylaluminum to the monophosphonate 5. A mechanism is suggested involving a transition state or intermediate with coordination of the trialkylaluminum to the migrating oxygen. Copyright Taylor & Francis Group, LLC.
P-chirogenic diphosphazanes with axially chiral substituents and their use in rh-catalyzed asymmetric hydrogenation
Moritz, Jan-Ole,Chakrabortty, Soumyadeep,Bernd H. Mu.ller,Spannenberg, Anke,Kamer, Paul C. J.
, p. 14537 - 14544 (2020/12/29)
A convenient synthesis of enantiopure P-chirogenic diphosphazanes incorporating bulky bisphenol and 1,1′-bi-2-naphtholderived substituents via the functionalization of a readily accessible enantiopure lithium phosphinoamide with chlorophosphoridites was developed. Since the product requires no subsequent deprotection, the protocol provides an easy, convenient synthesis of P-chirogenic ligands on the gram scale. The ligands were applied in the Rh-catalyzed asymmetric hydrogenation of benchmark substrates furnishing enantiomeric excess values up to 96%.
NOVEL MONOPHOSPHITE COMPOUNDS HAVING AN ETHER GROUP
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Paragraph 0183-0184, (2016/11/17)
Novel monophosphite compounds having an ether group, and a process for preparing these compounds, which are especially suitable for use as ligands in hydroformylation reactions.
Synthesis and Reactivity of Chiral, Wide-Bite-Angle, Hybrid Diphosphorus Ligands
Czauderna, Christine Fee,Cordes, David B.,Slawin, Alexandra M. Z.,Müller, Christian,Van Der Vlugt, Jarl Ivar,Vogt, Dieter,Kamer, Paul C. J.
, p. 1797 - 1810 (2014/04/17)
Effective and modular synthetic approaches toward phosphine-phosphite ligands and phosphine-phosphonite ligands featuring a diphenyl ether backbone have been developed. The phosphine-phosphite ligands are obtained by a two-step protocol from 2-bromo-2′-methoxydiphenyl ether. The phosphine-phosphonite ligands are prepared in a four-step synthetic protocol that involves a novel, unsymmetrical diphenyl ether derived phosphine-phosphorusdiamide as key building block. Structural studies on PtII complexes with either phosphine-phosphite or phosphine-phosphonite ligands indicate strict cis coordination for these ligand systems. High-pressure NMR spectroscopy studies of Rh complexes under syngas indicate the presence of two ea isomers for Rh(H)(CO)2(PP). The existence of this mixture is further supported by high-pressure IR spectroscopy studies. In order to benchmark the activity and selectivity of these novel, wide-bite-angle, mixed-donor ligands, they were screened in Pd-catalyzed asymmetric allylic alkylation as well as Rh-catalyzed hydrogenation and hydroformylation reactions. The ligands give 100-% conversion and low-to-moderate enantioselectivity in the allylic alkylation of 1,3-diphenyl-2-propenyl acetate and cyclohexyl-2-enyl acetate with dimethyl malonate. In the hydroformylation of styrene, good conversion and regioselectivities are achieved but only moderate enantioselectivity. The ligands give good conversions in asymmetric hydrogenation of typical substrates, with good-to-excellent enantioselectivities of up to 97-% depending on the substrate. Copyright
