Details

Autor(en) / Beteiligte

• Petrone, David A
• Isomura, Mayuko
• Franzoni, Ivan
• Rössler, Simon L
• Carreira, Erick M

Titel

Allenylic Carbonates in Enantioselective Iridium-Catalyzed Alkylations

Ist Teil von

• Journal of the American Chemical Society, 2018-04, Vol.140 (13), p.4697-4704

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• An enantioconvergent C­(sp3)–C­(sp3) coupling between racemic allenylic electrophiles and alkylzinc reagents has been developed. An Ir/(phosphoramidite,olefin) catalyst provides access to highly enantioenriched allenylic substitution products (93–99% ee) with complete regiocontrol (>50:1 rr in all cases) over the corresponding 1,3-diene isomers which are obtained predominantly when other metal catalysts are emplyed. The synthetic utility of the products obtained was highlighted in a variety of stereoselective transition metal-catalyzed difunctionalization reactions. Furthermore, a combination of experimental and theoretical studies provide support for a putative reaction mechanism wherein enantiodetermining C–C coupling occurs via nucleophilic attack on a highly planarized aryl butadienylium π-system that is coordinated to the Ir center in an η2-fashion.