Gas-Phase Generated Phosphinidenes as a Route to Phosphorus Heterocycles - Formation of the First 3H-Phosphindole

Abstract

Flash vacuum pyrolysis (FVP) over freshly resublimed magnesium on glass wool is a convenient and powerful dehalogenating procedure for a wide range of organic halides. We have now applied this system to the generation of phosphinidenes from the corresponding dichlorophosphines. As shown below, the production of phospholane from 1 and the interesting pyrophoric polymer 3 from 2 are readily explained by intramolecular insertion of the phosphinidenes. Under similar conditions 4 gives not only the expected phosphinidene insertion product, the phosphaindane 5, but also as a minor product, the 3-H-phosphaindene (“phosphindole”) 6 - the first example of a new heterocyclic system and the first 3-H-phosphole of any type.     

Petasis vs. Strecker Amino Acid Synthesis: Convergence,Divergence and Opportunities in Organic Synthesis

α-Amino acids find widespread applications in various areas of life and physical sciences. Their syntheses are carried out by a multitude of protocols, of which Petasis and Strecker reactions have emerged as the most straightforward and most widely used. Both reactions are three-component reactions using the same starting materials, except the nucleophilic species. The differences and similarities between these two important reactions are highlighted in this review.     

Synthesis and Evaluation of Chalcone-Quinoline Based Molecular Hybrids as Potential Anti-Malarial Agents

Molecular hybridization is a drug discovery strategy that involves the rational design of new chemical entities by the fusion (usually via a covalent linker) of two or more drugs, both active compounds and/or pharmacophoric units recognized and derived from known bioactive molecules. The expected outcome of this chemical modification is to produce a new hybrid compound with improved affinity and efficacy compared to the parent drugs. Additionally, this strategy can result in compounds presenting modified selectivity profiles, different and/or dual modes of action, reduced undesired side effects and ultimately lead to new therapies. In this study, molecular hybridization was used to generate new molecular hybrids which were tested against the chloroquine sensitive (NF54) strain of P. falciparum. To prepare the new molecular hybrids, the quinoline nucleus, one of the privileged scaffolds, was coupled with various chalcone derivatives via an appropriate linker to produce a total of twenty-two molecular hybrids in 11%–96% yield. The synthesized compounds displayed good antiplasmodial activity with IC₅₀ values ranging at 0.10–4.45 μM.