Search

Protecting group chemistry has invariably captured the fascination of chemists because of its extensive viability in chemical synthesis. The present report describes our pioneer work of applying ytterbium triflate as a catalyst, for the reaction of alcohols with di-tert-butyl dicarbonate (Boc2O) leading to the formation of tert-butyl ethers. There exists no recorded evidence for the use of Yb(OTf)3 as a catalyst for the protection of alcohols to tert-butyl ethers, despite its excellent utility in various reactions. Yb(OTf)3 has been used predominantly in the catalytic deprotection studies such as selective deprotection of tert-butyl esters to carboxylic acids as well as prenyl ethers to alcohols. This study involved the critical evaluation of solvent, time, and temperature that finally led to an efficient protocol for the formation of tert-butyl ethers. Yb(OTf)3 catalyzed the formation of tert-butyl ethers, notably reducing the reaction time, which is exemplified by the achievement of up to 92% conversion of alcohols to tert-butyl ethers within an hour. Additionally, the report demonstrates the utility of this synthetic protocol for the protection of carboxylic acids.

Malaria, even though an avoidable and treatable disease, can be fatal if ignored. Artemisinin Combination Therapy (ACT) and RTS, S/AS01 vaccine (Mosquirix™) are the only modest means available with humans to overcome malaria, a lethal affliction wreaking havoc across the globe. Employment of ACT is associated with problems such as ‘Artemisinin Resistance’ and the ‘Hypnozoite conundrum’ that hinder the complete eradication of malaria. In this view, the natural products specifically comprising β-carboline scaffold have shown good antiplasmodial responses against different strains of malaria. Taking these observations forward, researchers have performed structure-activity relationship (SAR) studies around three different β-carboline skeletons (tetrahydro β-carbolines, dihydro β-carbolines, β-carbolines) to design new β-carboline derived heterocyclic structures or modified naturally occurring derivatives. In addition, different approaches such as dimerization and linkage to other moieties have also been adopted to enhance the antimalarial activity. The present review describes a comprehensive SAR study encapsulating various natural and synthetic β-carbolines to elaborate upon the utility of these skeletons in designing drugs to subdue this deadly disease.