Ring Expansion of Silacyclobutanes with Allenoates to Selectively Construct 2- or 3-(E)-Enoate-Substituted Silacyclohexenes was written by Tang, Xiaoxiao;Zhang, Yan;Tang, Yulang;Li, Yi;Zhou, Jiajing;Wang, Duyang;Gao, Lu;Su, Zhishan;Song, Zhenlei. And the article was included in ACS Catalysis in 2022.Formula: C26H28FeNP This article mentions the following:
Silacycle is one of the most essential core frameworks in Si-containing functional mols. However, the structural diversity of silacycles was largely limited due to the lack of general synthetic methods. Here, the authors report an efficient synthesis of exo-cyclic enoate-substituted silacyclohexenes by the ring expansion of silacyclobutanes with allenoates. The reaction proceeds with two regioselectivities during Si-C bond insertion. In the presence of the Pd/PR3 catalyst, unsubstituted allenoates undergo β, γ-insertion to form a Si-Cβ bond, giving 2-(E)-enoate-substituted silacyclohexenes. In this pathway, a chiral phosphoramidite ligand was used to construct the stereogenic Si center enantioselectively. In the 2nd pathway, in the presence of the PtCl2 catalyst, α-substituted allenoates undergo γ, β-insertion to form a Si-Cγ bond, leading to 3-(E)-enoate-substituted silacyclohexenes. The control experiments and d. functional theory calculations were performed to understand the regio- and stereochem. outcome of both Pd- and Pt-catalyzed ring expansion reactions. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Formula: C26H28FeNP).
(R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2) belongs to chiral phosphine ligands. Phosphine-catalyzed asymmetric reactions are now powerful and versatile tools for the construction of C–C, C–N, C–O, and C–S bonds and for the syntheses of functionalized carbocycles and heterocycles. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Formula: C26H28FeNP
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis