Olaizola Iurre, Campano Teresa E, Iriarte Igor, Vera Silvia, Mielgo Antonia, García Jesús M, Odriozola José M, Oiarbide Mikel, Palomo Claudio
Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018, San Sebastián, Spain.
Departamento de Química Aplicada, Institute for Advanced Materials (INAMAT), Universidad Pública de Navarra, 31006, Pamplona, Spain.
Chemistry. 2018 Mar 12;24(15):3893-3901. doi: 10.1002/chem.201705968. Epub 2018 Feb 15.
The catalyst-controlled enantioselective direct addition reaction of enolizable esters and related carboxylic acid derivatives to π electrophiles remains a difficult synthetic transformation. In this study, the suitability of α-hydroxy ketones as ester equivalents capable of being activated by bifunctional Brønsted base catalysts in the context of conjugate addition reactions to nitroolefins is demonstrated. The scope of the reaction, which affords the corresponding Michael adducts with very high stereoselectivity (diastereomeric ratio (d.r.) ≥95:5, up to 99 % enantiomeric excess (ee)), and its limitations are explored, as is the aftermath elaboration of adducts into densely functionalized enantioenriched products.
可烯醇化酯及相关羧酸衍生物与π亲电试剂的催化剂控制对映选择性直接加成反应仍然是一种具有挑战性的合成转化反应。在本研究中，证明了α-羟基酮作为酯替代物在与硝基烯烃的共轭加成反应中能够被双功能布朗斯特碱催化剂活化的适用性。该反应能够以非常高的立体选择性（非对映体比例（d.r.）≥95:5，对映体过量（ee）高达99%）得到相应的迈克尔加成物，本文对其反应范围及其局限性进行了探索，同时也研究了将加成物进一步转化为功能密集的对映体富集产物的后续过程。
