Ni-catalyzed asymmetric hydrophosphinylation of conjugated enynes and mechanistic studies

• Published in: Chemical science (Cambridge) Vol. 13; no. 14; pp. 495 - 412
• Main Authors: Zhang, Ya-Qian, Han, Xue-Yu, Wu, Yue, Qi, Peng-Jia, Zhang, Qing, Zhang, Qing-Wei
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 06.04.2022; Royal Society of Chemistry; The Royal Society of Chemistry
• Subjects: Asymmetry; Chemical synthesis; Chemistry; Chemistry, Multidisciplinary; Density functional theory; Enantiomers; Ligands; Phosphine oxide; Physical Sciences; Science & Technology; Transition metals; PHOSPHORUS; HYDROPHOSPHORYLATION; INSERTION; LIGANDS; P-CHIRAL PHOSPHINES; C-P; SECONDARY PHOSPHINE OXIDES; ALKYNES; BORANES; ACCESS
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d2sc00091a

The catalytic asymmetric synthesis of P -stereogenic phosphines is an efficient strategy to access structurally diverse chiral phosphines that could serve as organocatalysts and ligands to transition metals and motifs of antiviral drugs. Herein, we describe a Ni catalyzed highly regio and enantioselective hydrophosphinylation reaction of secondary phosphine oxides and enynes. This method afforded a plethora of alkenyl phosphine oxides which could serve as valuable precursors to bidentate ligands. A new type of mechanism was discovered by combined kinetic studies and density functional theory (DFT) calculations, which was opposed to the widely accepted Chalk-Harrod type mechanism. Notably, the alkene moiety which could serve as a directing group by coordinating with the Ni catalyst in the transition state, plays a vital role in determining the reactivity, regio and enantioselectivity. A Ni-catalyzed hydrophosphinylation reaction of enynes was reported with excellent regio and enantioselectivity. A protonation mechanism was uncovered by combined kinetic studies and DFT calculations, which may lead to the discovery of other hydrofunctionalization reactions.