Acid and base catalysed reactions in one pot with site-isolated polyHIPE catalysts

Lewis acid-catalysed one pot synthesis of substituted xanthenes.

A direct synthesis of substituted xanthenes from salicylaldehydes and cyclohexenones or tetralones has been developed. The reaction is catalysed by Lewis acids like scandium triflate and furnishes substituted xanthenes in good to excellent yields using either microwave or thermal heating. Microwave heating results in significantly shortened reaction times of 30 min and generally higher yields.

Mesoporous Silica with Site-Isolated Amine and Phosphotungstic Acid Groups: A Solid Catalyst with Tunable Antagonistic Functions for One-Pot Tandem Reactions**

Scientists engaged in heterogeneous catalysis often cite enzymes as their model catalysts. Enzymes can efficiently catalyze multistep processes that give various types of biomolecules. Remarkably, many enzymes combine two antagonistic catalytic functions, such as acid and base functions. Attracted by this challenge, several groups synthesized homogeneous catalysts that can successfully combine ...

Multistep One-Pot Reactions Combining Biocatalysts and Chemical Catalysts for Asymmetric Synthesis

In a continuous effort to emulate the efficiency of biosynthetic pathways, considerable progress has been made in developing one-pot chemoenzymatic processes that take full advantage of the chemo-, regio-, and stereoselectivity of biocatalysts and the productivity of chemical catalysts. Over the last 20 years, research in this area has provided us with proof of concept examples in which chemica...

Site-isolated base- and acid-mediated Michael-initiated cyclization cascades.

Site isolated base and acid catalyzed azaspirocyclization cascades.

A one-pot, site isolated base (PS-BEMP) and acid (Si-TsOH) catalyzed cyclization cascade to azaspirocyclic molecules is reported; the reaction is simple to perform, atom efficient (water is the only byproduct) and broad in its scope to a diverse range of azaspirocyclic products.