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 conjugate addition 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
光学活性的季Δ的发散合成4 -和Δ 5 -脱氢脯氨酸是基于制定了关于第一催化对映选择性共轭加成的α取代的异(硫代)乙酸盐以乙烯基酮是一般两个α -芳基和α -烷基异氰基(硫代)乙酸盐。由于双官能叔胺/方胺催化剂的存在,不需要任何金属盐就可以形成新的四取代的C-N立体中心,它具有庞大的聚芳基侧链和固态时方胺间的距离非常短。