A DABCO-catalyzed (3 + 3) annulation between 2-(acetoxymethyl)buta-2,3-dienoate and sulfur ylides has been developed, which provides a facile method for the synthesis of 4H-pyrans bearing a vinyl sulfide group.

An expedient asymmetric total synthesis of aspidophytine is reported. A highly convergent strategy involving the sequential annulation of vinyl iodide 5 with indole 6 exploits varying modes of indole reactivity to provide aspidophytine in 23% over six steps from 5.

An efficient method towards synthesis of 1,10-phenanthrolines is described. Through Lewis acid-catalyzed annulation reaction between 3-ethoxycyclobutanones and 8-aminoquinolines, a variety of unsymmetric and symmetric 1,10-phenanthroline derivatives were readily prepared with high regioselectivity at room temperature.

a highly efficient, simple and green solvent-free protocol for the preparation of poly-substituted quinolines via friedländer hetero-annulation reaction between 2-aminoaryl ketones and carbonyl compounds in the presence of silica-supported p2o5 (p2o5 / sio2) is described. in this method, the title compounds are obtained in high to excellent yields and in short reaction times.

The lateral CC-π-extension of perylene diimides ( PDI s) to coronene CDI leads undesired effects such as the decrease absorption and a hypsochromic shift. This could be overcome by BN-annulation s form superior BNCDIs .

Catalytic C-H activation and hydroamination represent two important strategies for eco-friendly chemical synthesis with high atom efficiency and reduced waste production. Combining both C-H activation and hydroamination in a cascade process, preferably with a single catalyst, would allow rapid access to valuable nitrogen-containing molecules from readily available building blocks. Here we repor...

Larger condensed arenes are of interest owing to their electro- and photochemical properties. An efficient synthesis is the catalyzed aromatic annulation of a smaller arene with two alkyne molecules. Besides difunctionalized starting materials, directed C-H functionalization can be used for such aromatic homologation. However, thus far the requirement of either pre-functionalized substrates or ...

Theoretical calculations were carried out to understand the effect of annulation on the electronic and ligand properties of boron substituted N-heterocyclic carbenes (B-NHCs). Annulation results in a decrease in stability as indicated by the calculated values of singlet-triplet separations and stabilization energies as well as HOMO-LUMO gaps. Annulated B-NHCs are found to be weaker σ-donors but...

A highly efficient, simple and green solvent-free protocol for the preparation of poly-substituted quinolines via Friedländer hetero-annulation reaction between 2-aminoaryl ketones and carbonyl compounds in the presence of silica-supported P2O5 (P2O5 / SiO2) is described. In this method, the title compounds are obtained in high to exc...

Substantial progress has been described in the development of asymmetric variants of the phosphine-catalyzed intermolecular [3+2] annulation of allenes with alkenes; however, there have not been corresponding advances for the intramolecular process, which can generate a higher level of complexity (an additional ring and stereocenter(s)). In this study, we describe the application of chiral phos...