A Spatially Orthogonal Hierarchically Porous Acid-Base Catalyst for Cascade and Antagonistic Reactions

Complex organic molecules are of great importance to academic and industrial chemistry and typically synthesised from smaller building blocks by multistep reactions. The ability to perform multiple (distinct) transformations in a single reactor would greatly reduce the number of manipulations required for chemical manufacturing, and hence the development of multifunctional catalysts for such one-pot reactions is highly desirable. Here we report the synthesis of a hierarchically porous framework, in which the macropores are selectively functionalised with a sulfated zirconia solid acid coating, while the mesopores are selectively functionalised with MgO solid base nanoparticles. Active site compartmentalisation and substrate channelling protects base catalysed triacylglyceride transesterification from poisoning by free fatty acid impurities (even at 50 mol%), and promotes the efficient two-step cascade deacetylation-Knoevenagel condensation of dimethyl acetals to cyanoates.