Enantioselective Synthesis of Quaternary Δ<sup>4</sup>
- and Δ<sup>5</sup>
-Dehydroprolines Based on a Two-Step Formal [3+2] Cycloaddition of α-Aryl and α-Alkyl Isocyano(thio)acetates with Vinyl Ketones
作者:Amaiur Odriozola、Mikel Oiarbide、Claudio Palomo
DOI:10.1002/chem.201703526
日期:2017.9.18
of optically active quaternary Δ4‐ and Δ5‐dehydro prolines is developed based on the first catalytic enantioselective conjugateaddition of α‐substituted isocyano(thio)acetates to vinyl ketones that is general for both α‐aryl and α‐alkyl isocyano(thio)acetates. The new tetrasubstituted C−N stereocenter is formed without the need of any metal salt due to a bifunctional tertiary amine/squaramide catalyst