Construction of Vicinal Quaternary Centers via Iridium-Catalyzed Asymmetric Allenylic Alkylation of Racemic Tertiary Alcohols
| Autor: | David A. Petrone, Erick M. Carreira, Mayuko Isomura |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Olefin fiber
Phosphoramidite Silylation Allene Enantioselective synthesis Ketene Regioselectivity General Chemistry Alkylation 010402 general chemistry 01 natural sciences Biochemistry Combinatorial chemistry Catalysis 0104 chemical sciences chemistry.chemical_compound Colloid and Surface Chemistry chemistry |
| Zdroj: | Journal of the American Chemical Society. 143:3323-3329 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Enantioselective bond formation between sterically hindered fragments to furnish acyclic products with vicinal quaternary centers is a formidable challenge. We report a solution that involves cocatalysis between a chiral Ir-(phosphoramidite,olefin) complex and La(OTf)3. This robust catalytic system effects highly enantioconvergent and regioselective alkylation of racemic tertiary α-allenyl alcohols with tetrasubstituted silyl ketene acetals. The transformation displays broad functional group tolerance for both reaction components and allows efficient generation of β-allenyl ester products in good yield and with excellent enantioselectivity. Furthermore, both the allene and ester functionalities were leveraged to upgrade the structural complexity of the products via a series of stereoselective metal-catalyzed functionalization reactions. |
| Databáze: | OpenAIRE |
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