Catalytic Asymmetric Synthesis of α-Quaternary Proline Derivatives by 1,3-Dipolar Cycloaddition of α-Silylimines was written by Hernandez-Toribio, Jorge;Padilla, Silvia;Adrio, Javier;Carretero, Juan C.. And the article was included in Angewandte Chemie, International Edition in 2012.Application of 133545-16-1 This article mentions the following:
We report an efficient asym. protocol for the CuI-catalyzed 1,3-dipolar cycloaddition of α-silylimines to activated olefins. A variety of α-quaternary proline derivatives were obtained with good yields and excellent levels of diastereoselectivity and enantiocontrol with a variety of dipolarophiles, such as maleimides and α,β-unsaturated sulfones (up to 99% ee). The use of the bulky DTBM-Segphos ligand proved to be crucial for attaining this high enantioselectivity. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Application of 133545-16-1).
(R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Application of 133545-16-1
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis