Synthesis of benzannulated spiroacetals using chiral gold-phosphine complexes and chiral anions was written by Quach, Rachelle;Furkert, Daniel P.;Brimble, Margaret A.. And the article was included in Tetrahedron Letters in 2013.Quality Control of (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) This article mentions the following:
The development of an asym. gold-catalyzed dihydroalkoxylation strategy for the synthesis of the 3’H-spiro[chroman-2,1′-isobenzofuran] spiroketal ring system I is described. Spiroacetal I was generated in up to 87:13 enantiomeric ratio using chiral gold-phosphine complexes and chiral silver phosphate Ag(S)-TRIP. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Quality Control of (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine)).
(R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Quality Control of (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine)
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis