On the asymmetric iridium-catalyzed N-allylation of amino acid esters: Improved selectivities through structural variation of the chiral phosphoramidite ligand was written by Albat, Dominik;Kocher, Alicia;Witt, Julia;Schmalz, Hans-Guenther. And the article was included in European Journal of Organic Chemistry in 2022.SDS of cas: 252288-04-3 This article mentions the following:
The investigation of the iridium-catalyzed asym. N-allylation of tert-Bu glycinate using a “branched” racemic 1-vinyl-alkyl Me carbonate revealed severe limitations of existing protocols. By screening a set of 24 BINOL-derived chiral phosphoramidites a new superior ligand (L24*) was identified which afforded the amination product with high enantioselectivity (≥95% ee) under optimized conditions. This ligand also allowed the N-allylation of other amino acid tert-Bu esters (derived from alanine, phenylalanine, or proline) with outstanding levels of diastereocontrol (d.r. ≥99 : 1) and negligible matched/mismatched differences. 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: 252288-04-3SDS of cas: 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. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.SDS of cas: 252288-04-3
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis