Highly Enantioselective Conjugate Additions of Potassium Organotrifluoroborates to Enones by Use of Monodentate Phosphoramidite Ligands was written by Duursma, Ate;Boiteau, Jean-Guy;Lefort, Laurent;Boogers, Jeroen A. F.;De Vries, Andre H. M.;De Vries, Johannes G.;Minnaard, Adriaan J.;Feringa, Ben L.. And the article was included in Journal of Organic Chemistry in 2004.Application of 252288-04-3 This article mentions the following:
The use of phosphoramidite ligands in the rhodium-catalyzed asym. conjugate addition of potassium organotrifluoroborates to various enones in the absence of water is described. A systematic search for effective catalysts has been performed by use of high-throughput screening methods. Initially, reaction conditions and catalyst precursors, and ligand libraries were screened. In the next stage a monodentate ligand combination approach was used, and finally a library of 96 different phosphoramidites was prepared by parallel synthesis using a robot (instant ligand libraries) and these were tested in the vinylation of cyclohexenone (up to 88% enantiomeric excess, ee) and 4-phenyl-3-buten-2-one (up to 42% ee). Arylation of cyclohexenone by use of potassium (phenyl)trifluoroborate gave 3-phenylcyclohexanone with 99% ee. In the experiment, the researchers used many compounds, for example, (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3Application of 252288-04-3).
(11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Application of 252288-04-3
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis