Li, Chen-Long; Yang, Yusheng; Zhou, Yi; Yu, Zhi-Xiang published an article on January 31 ,2022. The article was titled 《A Formal [3+3+1] Reaction of Enyne-Methylenecyclopropanes through Au(I)-Catalyzed Enyne Cycloisomerization and Rh(I)-Catalyzed [6+1] Reaction of Vinylspiropentanes and CO》, and you may find the article in Asian Journal of Organic Chemistry.Electric Literature of C50H56O14P2 The information in the text is summarized as follows:
A formal [3+3+1] reaction through gold(I)-catalyzed enyne cycloisomerization of enyne-methylenecyclopropanes I (R1 = H, Me, Bn, n-Bu, 4-trifluoromethylphenyl; R2 = H, Me, Ph; R3 = H, Me; X = 2-nitrobenzenesulfonamido, benzenesulfonamido, 4-bromobenzenesulfonamido, O) and rhodium(I)-catalyzed [6+1] reaction of vinylspiropentanes II and CO has been developed to synthesize aza-6/7 bicyclic compounds, hexahydrocyclohepta[c]pyridinones III. DFT calculations reveal that four steps are involved in the [6+1] cycloaddition of vinylspiropentanes II and CO, including oxidative addition of cyclopropane to Rh, β-C elimination, CO insertion and reductive elimination. The experimental part of the paper was very detailed, including the reaction process of (R)-(6,6′-Dimethoxybiphenyl-2,2′-diyl)bis[bis(3,4,5-trimethoxyphenyl)phosphine](cas: 256390-47-3Electric Literature of C50H56O14P2)
(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. Electric Literature of C50H56O14P2
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis