Indium-Catalyzed Annulation of 2-Aryl- and 2-Heteroarylindoles with Propargyl Ethers: Concise Synthesis and Photophysical Properties of Diverse Aryl- and Heteroaryl-Annulated[<i>a</i>]carbazoles
is applicable also to symmetrical dimers such as bithiophene and bifuran derivatives. Mechanisticstudies suggest that the first step is addition reaction initiated by regioselective nucleophilic attack of the C3 of 2-aryl- and 2-heteroarylindoles to the internal carbon atom of the C[triple bond]C bond in propargyl ethers. The next stage is ring-closing S(N)2 process kicking out the alkoxy group and
Recent work has shown that a new K2FeO4 based oxidation protocol can promote a highly unusual carbon-carbon bond cleaving reaction of functionalised propargylalcohols.
A combination of zinc triflate and pyridine in a nitrile medium was found to act as an effective catalytic system for dehydrogenativesilylation with flexible pieces of terminalalkynes and hydrosilanes, thereby producing diverse alkynylsilanes in high to excellent yields.
Six series of semisynthetic lipophilic glycopeptideantibiotic derivatives were evaluated for in vitro activity against influenza A and B viruses. The new teicoplanin pseudoaglycon-derived lipoglycopeptides were prepared by coupling one or two side chains to the N-terminus of the glycopeptide core, using various conjugation methods. Three series of derivatives bearing two lipophilic groups were synthesized