The mechanism studies of catalytic chemoselective conjugate addition of amino alcohols to α,β-unsaturated ester

• Published in: Theoretical chemistry accounts Vol. 140; no. 1
• Main Authors: Han, Peilin, Han, Huijuan, Zhang, Xiaowei, Hou, Xiaoxiao, Wang, Hui, Liu, Chunhui
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2021; Springer Nature B.V
• Subjects: Alcohols; Amines; Atomic/Molecular Structure and Spectra; Chemistry; Chemistry and Materials Science; Esters; Inorganic Chemistry; Lewis acid; Organic Chemistry; Physical Chemistry; Regular Article; Silver; Theoretical and Computational Chemistry; Reaction mechanisms; Chemoselectivity; Lewis acid/Brønsted base pair catalyst
• ISSN: 1432-881X; 1432-2234
• DOI: 10.1007/s00214-020-02711-y

The competing mechanisms of silver-/aminolithium-catalyzed hydrofunctionalization of α , β -unsaturated ester with an amino alcohol have been systematically studied with the DFT methods. Here, the acidity of a weaker nucleophile OH group of an amino alcohol is significantly higher than that of NH 2 group, so it is easy to deprotonate by Ag(HMDS)/dppe. However, the generated Ag–O bond is more stable than the corresponding Ag–N bond. Therefore, the OH group shows higher reactivity than the NH 2 group in the presence of a Lewis acid/Brønsted base pair catalyst. Then, α , β -unsaturated esters can be inserted into corresponding Ag–O bonds to obtain alkyl silver species. Alkyl silver can be protonated by bis(trimethylsilyl)amines to obtain hydrogen functionalized products and regenerate silver amino active compounds Ag(HMDS)/dppe.