Lipidic Mesophases as Novel Nanoreactor Scaffolds for Organocatalysts: Heterogeneously Catalyzed Asymmetric Aldol Reactions in Confined Water

The unique molecular architecture of lipidic cubic phases (LCPs) and their cubosome dispersions comprise a well-defined, curved bilayer that spans the entire three-dimensional (3-D) material space, encompassing a network of two periodic, curved, and nonintersecting 3-D aqueous channels. The ensuing large lipid/water interfacial area makes these biomaterials an interesting matrix for the lateral immobilization of organocatalysts to catalyze organic reactions in confined water. Herein, we report for the first time the design, synthesis, assembly, and characterization of catalytically active LCPs and cubosomes and demonstrate their applicability as self-assembled, biomimetic, and recyclable nanoreactor scaffolds. Small-angle X-ray scattering, cryo-transmission electron microscopy, and dynamic light scattering were applied for the characterization of the mesophases. These mesophases can be recycled and enable efficient catalytic activity as well as modulation of the diastereo- and enantioselectivity for the aldol reaction of several benzaldehyde derivatives and cyclohexanone in water.