Synthetic Route of C50H56O14P2On October 7, 2016 ,《Rh-Catalyzed Conjugate Addition of Arylzinc Chlorides to Thiochromones: A Highly Enantioselective Pathway for Accessing Chiral Thioflavanones》 was published in Organic Letters. The article was written by Meng, Ling; Jin, Ming Yu; Wang, Jun. The article contains the following contents:
A highly efficient asym. synthesis of chiral thioflavanones is developed via conjugate addition of arylzinc reagents to thiochromones using [Rh(COD)Cl]2/(R)-3,4,5-MeO-BIPHEP catalyst. This method overcomes catalyst poisoning and substrate inertness and affords a series of chiral thioflavanones (2-arylthiochroman-4-ones) in good yields (up to 91% yield) with excellent ee values (up to 97% ee). The established asym. synthesis paves the way for further pharmaceutical studies.(R)-(6,6′-Dimethoxybiphenyl-2,2′-diyl)bis[bis(3,4,5-trimethoxyphenyl)phosphine](cas: 256390-47-3Synthetic Route of C50H56O14P2) was used in this study.
(R)-(6,6′-Dimethoxybiphenyl-2,2′-diyl)bis[bis(3,4,5-trimethoxyphenyl)phosphine](cas: 256390-47-3) belongs to chiral phosphine ligands. Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates. These intermediates are formed through nucleophilic attack of the phosphine catalysts at electron-poor nuclei (normally carbon atoms) and then proceed through several steps to form new chemical bonds. Synthetic Route of C50H56O14P2
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis