Asymmetric Rh(I)-catalyzed intramolecular [3 + 2] cycloaddition of 1-yne-vinylcyclopropanes for bicyclo[3.3.0] compounds with a chiral quaternary carbon stereocenter and density functional theory study of the origins of enantioselectivity was written by Lin, Mu;Kang, Guan-Yu;Guo, Yi-An;Yu, Zhi-Xiang. And the article was included in Journal of the American Chemical Society in 2012.Category: chiral-phosphine-ligands This article mentions the following:
A highly enantioselective Rh(I)-catalyzed intramol. [3 + 2] cycloaddition of 1-yne-VCPs to bicyclo[3.3.0] compounds with an all-carbon chiral quaternary stereocenter at the bridgehead carbon was developed. DFT calculations of the energy surface of the catalytic cycle (complexation, cyclopropane cleavage, alkyne insertion, and reductive elimination) of the asym. [3 + 2] cycloaddition reaction indicated that the rate- and stereo-determining step is the alkyne-insertion step. Anal. of the alkyne-insertion transition states revealed that the serious steric repulsion between the substituents in the alkyne moiety of the substrates and the rigid H8-BINAP backbone is responsible for not generating the disfavored [3 + 2] cycloadducts. In the experiment, the researchers used many compounds, for example, (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) (cas: 37002-48-5Category: chiral-phosphine-ligands).
(((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) (cas: 37002-48-5) belongs to chiral phosphine ligands. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Category: chiral-phosphine-ligands
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis