Pyrimidine-Derived Prolinamides as Recoverable Bifunctional Organocatalysts for Enantioselective Inter- and Intramolecular Aldol Reactions under Solvent-Free Conditions
作者:Pascuala Vizcaíno-Milla、José M. Sansano、Carmen Nájera、Béla Fiser、Enrique Gómez-Bengoa
DOI:10.1002/ejoc.201500007
日期:2015.4
ChiralL-prolinamides 2 containing the (R,R)- and (S,S)-trans-cyclohexane-1,2-diamine scaffold and a 2-pyrimidinyl unit are synthesized and used as general organocatalysts for intermolecular and intramolecular aldolreactions with 1,6-hexanedioic acid as a co-catalyst under solvent-free conditions. The intermolecular reaction between ketone–aldehyde and aldehyde–aldehyde must be performed under wet
Recoverable silica-gel supported binam-prolinamides as organocatalysts for the enantioselective solvent-free intra- and intermolecular aldol reaction
作者:Abraham Bañón-Caballero、Gabriela Guillena、Carmen Nájera、Enrico Faggi、Rosa María Sebastián、Adelina Vallribera
DOI:10.1016/j.tet.2012.11.097
日期:2013.1
supported binam-derived prolinamides are efficient organocatalysts for the direct intramolecular and intermolecular aldol reaction under solvent-free conditions using conventional magnetic stirring. These organocatalysts in combination with benzoic acid showed similar results to those obtained under similar homogeneous reaction conditions using an organocatalyst of related structure. For the intermolecular process
primary amine catalyzed efficient and practical protocol for the large-scale synthesis of Wieland–Miescher and Hajos–Parrishketones as well as their analogues. This article describes a simple chiral primary amine catalyzed efficient and practical protocol for the large-scale synthesis of Wieland–Miescher and Hajos–Parrishketones as well as their analogues.
A series of Wieland-Miescher ketone analogues bearing highly functionalized substituents are efficiently constructed in high enantioselectivities and good yields using catalytic amounts of prolinamide and PPTS. We have successfully utilized this reaction as a key step to synthesize the tricyclic core of cylindricine type alkaloids.
efficient and practical protocol for the synthesis of both Wieland–Miescher ketone and Hajos–Parrishketone as well as their analogues. The reaction can be conducted in gram scale with 1% mol catalyst loading producing high enantioselectivity (up to 96% ee) and excellent yields (up to 98%). This procedure represents one of the most efficient methods for the synthesis of these versatile chiral building blocks