Asymmetric cyclocarbonylation of 1,6-enynes with cobalt catalysts was written by Schmid, Thomas M.;Consiglio, Giambattista. And the article was included in Tetrahedron: Asymmetry in 2004.Category: chiral-phosphine-ligands This article mentions the following:
Octacarbonyldicobalt or Co(II) salts in the presence of (R)-(6,6′-dimethoxybiphenyl-2,2′-diyl)bis(diphenylphosphine) were active and highly enantioselective catalyst for the cyclocarbonylation of enynes such as 4,4-bis(carboethoxy)hex-6-en-1-yne. The reactivity of both catalytic systems towards cyclocarbonylation increased when the CO pressure was increased. However, when a stoichiometric amount of ligand was used, with respect to the catalyst, the enantioselectivity decreased, but increased again as the ligand-to-Co molar ratio increased. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Category: chiral-phosphine-ligands).
(R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1) 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.Category: chiral-phosphine-ligands
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis