The PdCl(2)-promoted reactions of methylenecyclopropanes (MCPs) 1 bearing diaryl substituents on the terminal double bond were carefully investigated. The solvents employed significantly affected the reaction outcomes. It was found that dimeric allylpalladium(ii) complexes 2a-2f can be obtained as the sole products in acceptable to good yields under mild reaction conditions with THF as the solv...

Facile synthesis of coumarin via the tandem reaction of salicylaldehyde with aryl-substituted 1,1-dibromo-1-alkene was developed. This new protocol proceeds smoothly under mild and transition-metal-free conditions, it allows rapid access to coumarins containing various heteroatoms that are more difficult to prepare by traditional methods. Based on the isolated intermediate of 4-(diethylamino)-3...

An effective and facile method for the synthesis of 2,2-di-substituted perhydrofuro[2,3-b]pyran (and furan) derivatives is described. The cyclization of 1,2-cyclopropanated sugars with olefins in the presence of BiCl3 is highly diastereoselective. 2,2-Di-substituted cyclization products were obtained in good to excellent yields.

A series of novel benzimidazole derivatives 3-10 were synthesized. Benzimidazolyl-substituted acrylonitriles 3 and 4 underwent a photochemical dehydrocyclization reaction to give the corresponding mono- and dicyano-substituted benzimidazo[1,2-a] quinolines 5 and 6. Pinner reaction of these compounds did not give the expected mono- and diamidines, but rather only compounds 7-10, with amido group...

A divanadium-substituted phosphotungstate TBA(4)[γ-HPV(2)W(10)O(40)] (TBA = tetra-n-butylammonium) could act as an effective homogeneous catalyst for the H(2)O(2)-based oxidative bromination.

A series of donor-acceptor molecules, featuring intense low-energy intramolecular charge-transfer bands, was prepared by regioselective [2 + 2] cycloaddition between 7,7,8,8-tetracyanoquinodimethane (TCNQ) and N,N-dialkylanilino-substituted (DAA-substituted) alkynes, followed by ring opening of the initially formed cyclobutenes.

A combined theoretical and experimental study on the structure, infrared, UV-Vis and 1H NMR data of trans-2-(m-cyanostyryl)pyridine, trans-2-[3-methyl-(m-cyanostyryl)]pyridine and trans-4-(m-cyanostyryl)pyridine is presented. The synthesis was carried out with an efficient Knoevenagel condensation using green chemistry conditions. Theoretical geometry optimizations and their IR spectra were ca...

Hexacarbonyldicobalt complexes of biaryl-substituted 4-methoxybutynones and 4-methoxy-2-butynes undergo intramolecular Nicholas reactions to form dibenzocyclooctyne-Co2(CO)6 complexes in good yields. Reductive decomplexation of the cyclization products is possible, and the method has been applied to a formal synthesis of isoschizandrin.

The conversion of 3,4-dialkoxy-benzenes into dialkoxy-benzo-1,3,2-dithiazolyls is described and representative examples (1 and 2) derived from benzodioxole and veratrol, respectively, are reported. Whilst 1 is a dimeric pi*-pi* dimer, the dimethoxy derivative 2 is monomeric in the solid state and exhibits antiferromagnetic interactions.

Donor-substituted 1,1,2,4,4-pentacyanobuta-1,3-dienes and a cyclohexa-2,5-diene-1,4-diylidene-expanded derivative were prepared by a [2 + 2] cycloaddition of tetracyanoethene (TCNE) or 7,7,8,8-tetracyanoquinodimethane (TCNQ) to anilino-substituted cyanoalkynes, followed by retro-electrocyclisation; they feature intense bathochromically-shifted intramolecular charge-transfer bands and undergo th...