Asymmetric Synthesis of C2-Symmetric Axially Chiral Biaryls through Rhodium-Catalyzed and Alkyne-Controlled Diastereoselective Double [2+2+2]Cycloaddition was written by Mori, Ayaka;Araki, Tatsuya;Miyauchi, Yuta;Noguchi, Keiichi;Tanaka, Ken. And the article was included in European Journal of Organic Chemistry in 2013.Computed Properties of C29H30P2 This article mentions the following:
The asym. synthesis of C2-sym. axially chiral biaryls was achieved by the cationic rhodium(I)/1,3-bis(diphenylphosphino)propane (dppp) complex catalyzed diastereoselective double [2+2+2]cycloaddition of (R)-3-butyn-2-ol-derived tetraynes with functionalized monoynes. Interestingly, the use of propiolate derivatives afforded biaryls possessing large dihedral angles, and in contrast, the use of propargyl alc. afforded biaryls possessing small dihedral angles. The title compounds thus formed included an isobenzofuran dimer (I) and related substances. Under optimized reaction conditions, the synthesis of the target compounds was achieved using bis(norbornadiene)rhodium(I) tetrafluoroborate and 1,1′-(1,3-propanediyl)bis[1,1-diphenylphosphine] as catalyst combination. The synthesis of the target compounds was achieved by a reaction of chiral 1,6-bis(2-butyn-1-yloxy)-2,4-hexadiyne, 1,6-bis(2-propyn-1-yloxy)-2,4-hexadiyne, 1,1′-[(2,4-hexadiyne-1,6-diyl)bis(oxy-1-propyne-3,1-diyl)]bis[benzene] with alkyne derivatives In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Computed Properties of C29H30P2).
(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Many phosphine-catalyzed reactions have been developed for the syntheses of various biologically important acyclic and cyclic molecules. Asymmetric variants of these reactions have evolved relatively slowly. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Computed Properties of C29H30P2
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis