Here, we report insights into the new recyclable catalyst 1, (DMAP·saccharin). The DMAP·saccharin-catalysed acylation of alcohols has been successfully carried out more than 8 times. Only 1 mol% of catalyst 1 efficiently promotes acylation with almost equimolar amounts of acid anhydrides, under both base-free and solvent-free conditions.

The present study has been focused on the acid and base transesterification of animal fats (dairy cow and beef) to produce biodiesel by varying process parameters such as catalyst amount, catalyst nature, reaction time and temperature. The maximum biodiesel yield after acid catalysis was 94.1 ± 2.43 and 98.4 ± 2.3 percent for dairy cow and beef t...

In the ribozyme from the hepatitis delta virus (HDV) genomic strand RNA, a cytosine side chain is proposed to facilitate proton transfer in the transition state of the reaction and, thus, act as a general acid-base catalyst. Mutation of this active-site cytosine (C75) reduced RNA cleavage rates by as much as one million-fold, but addition of exogenous cytosine and certain nucleobase or imidazol...

There is significant interest in broadening the type of catalyst substrates that support the growth of high-quality carbon nanotube (CNT) carpets. In this study, ion beam bombardment has been utilized to modify catalyst substrates for CNT carpet growth. Using a combination of contact angle measurements (CAMs) and X-ray reflectivity (XRR) for the first time, new correlations between the physicoc...

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 ...

This chapter deals with acid–base bifunctional heterogeneous catalyst surfaces with organofunctional groups. One of the most important issues for bifunctional heterogeneous catalysis is the coexistence of incompatible catalytic species, such as acid and base, nearby on a same solid particle surface. In nucleophilic reactions, acid–base bifunctional catalysts enable the activation of both nucleo...

A new polymer acid catalyst, sulfonated hyperbranched poly(arylene oxindole), 5-OH-SHPAO, was prepared for selective cellulose hydrolysis. Its superior catalysis, showing high glucose selectivity at almost full cellulose conversion, is attributed to the presence of an hydroxyl group next to the sulfonic acid, therefore mimicking the separate acid-base pair in the cellulase active site.

This review describes our recent efforts in the development of acid-base organocatalysts, (S)-3-(N-isopropyl-N-3-pyridinylaminomethyl) BINOL (6a) and (S)-3-[2-(diphenylphosphino)phenyl] BINOL (13a), with dual activation mechanism for the aza-Morita-Baylis-Hillman (aza-MBH) reaction. In these catalysts, chiral Brønsted acid units are connected with a Lewis base unit via a spacer. The acid-base m...