Rhodium-catalyzed enantioselective 1,4-additions of arylboronic acids to substituted enones was written by Mediavilla Urbaneja, Laura;Krause, Norbert. And the article was included in Tetrahedron: Asymmetry in 2006.Formula: C24H22NO2P This article mentions the following:
The rhodium-catalyzed enantioselective 1,4-addition of (aryl)boronic acids to bifunctional Michael acceptors in the presence of phosphoramidite ligands occurs regioselectively at the endocyclic carbon-carbon double bond and in up to 95% ee. The presence of KOH is required to increase the reactivity so that less boronic acid and lower reaction temperatures can be used. The corresponding addition to a chiral enone (i.e., 6-methyl-2-cyclohexen-1-one) takes place with epimerization of the product to the thermodynamically more stable trans-isomer, which was obtained with up to 98% 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: 252288-04-3Formula: C24H22NO2P).
(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. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Formula: C24H22NO2P
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis