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Research has been conducted on the selective reduction of alkynes to alkenes. Results demonstrate that the use of indium in aqueous ethanol provides a highly selective reduction of the terminal alkynes to alkenes in aryl propargyl ethers, amines and esters.

A study was conducted to determine the applicability of ammonium formate/Pd-C in reducing the C=C bond in alpha,beta-unsaturated sulfones and phosphonates. The results showed that the substituents on the aromatic ring do not affect the process of hydrogenation. The method led to high yields of products at mild reaction conditions. It is also operationally simple and the reagents are easily available and relatively cheaper.

The catalytic efficiency of mixed Cu(I)-Cu(II) system in situ generated by partial reduction of CuSO4 with glucose in ethanol (nonanhydrous) under open air has been explored. With this catalysis, the multicomponent cascade reaction of A³-coupling of heterocyclic amidine with aldehyde and alkyne, 5-exo-dig cycloisomerization, and prototropic shift has afforded an efficient and eco-friendly synthesis of therapeutically important versatile N-fused imidazoles. Diverse heterocyclic amidines, several of which are known to be poorly reactive, and aldehydes are compatible in this catalytic process. [ABSTRACT FROM AUTHOR]

An efficient method for regio- and chemoselective Friedel-Crafts acylation of indole using acyl chlorides in the presence of ZrCl4 has been discovered. It minimizes/eliminates common competing reactions that occur due to high and multiatom-nucleophilic character of indole. In this method, a wide range of aroyl, heteroaroyl alkenoyl, and alkanoyl chlorides undergo smooth acylation with various indoles without NH protection and afford 3-acylindoles in good to high yields. [ABSTRACT FROM AUTHOR]

Scaffold-hopping of bioactive natural product aurones has been studied for the first time. 2-Arylideneimidazo[1,2- a ]pyridinones as potential topoisomerase IIα (hTopoIIα)-targeting anticancer compounds were considered. A multifunctional activator, polyphosphoric acid, enabled to realize a cascade reaction of 2-aminopyridine with 2,3-epoxyesters toward synthesis of 2-arylideneimidazo[1,2- a ]pyridinones. Most of the compounds exhibited hTopoIIα-selective poison activity with efficiency more than etoposide and DNA-binding property, while not interacting with hTopo I. The compounds showed pronounced antiproliferative activities in nanomolar range with relatively poor toxicity to normal cells, inhibition of invasiveness, and apoptotic effect. The activities for inhibition of tubulin assembly, CDK1 and pCDK1, were also observed. Interestingly, the hTopoIIα inhibitory (in vitro and ex vivo studies) and antiproliferative activities of representative potent compounds were found to be manifold higher compared to corresponding parent aurones bearing alike substitutions, indicating the importance of such scaffold-hopping strategy in medicinal chemistry research.