A palladium-catalyzed reaction of 2-alkynylhalobenzenes with 2-alkynylphenols in the presence of PCy(3) is discovered, which provides an efficient and facile route to indeno[1,2-c]chromenes. This reaction works efficiently, leading to the corresponding products in good to excellent yields.

The characteristic indeno-tetrahydropyridine core of cytotoxic haouamine B (2) was efficiently synthesized featuring the diastereoselective construction of a diaryl-substituted stereogenic quaternary center by an intramolecular Pd-catalyzed α-C-arylation and subsequent direct conversion of the vinylogous imide function into the C2-C25 double bond by TsNHNH(2).

The chiral N-heterocyclic carbene/Lewis acid co-catalyzed reaction of 2-aroylvinylcinnamaldehydes produced good yields of indeno[1,2-c]furan-1-one derivatives with excellent enantioselectivity and diastereoselectivity. A switch of intramolecular cyclization to intermolecular dimerization was achieved by the cooperative catalysis of chiral triazole carbene and Ti(OPr-i)4 catalysts.

Vilsmeier-Haack reaction of 2,3,3-trimethyl-3H-benzo[g]indole, then aqueous basic work-up, leads to benzo[g]indol-2-ylidene- malondialdehydes. These react with various arylhydrazines and quinolin-2-ylhydrazine to form 3,3-dimethyl-2-(1-aryl-1H-pyrazol-4-yl)- 3H-benzo[g]indoles in good yields.

A new synthetic route to indeno[1,2-b]quinolines via reactions of o-propargylbenzaldehydes with N-aryl amines based on an intramolecular aza-Diels-Alder (Povarov) reaction has been developed. This method offers several advantages such as no requirement for an oxidant, high efficiency, and a wide reaction scope.

Methyl 1-aryl-3-cinnamoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates interact with 3-(arylamino)-1H-inden-1-ones to give the corresponding 1,1'-diaryl-3'-cinnamoyl-4'-hydroxy-1H-spiro[indeno[1,2-b]pyrrole-3,2'-pyrrole]-2,4,5'(1'H)-triones in good yields.

background: asphalt workers are exposed to dangerous agents in his workplace that might result in occupational diseases. benzo (a) pyrene as a human carcinogen, is emission from hot asphalt and asphalt workers are exposed with it. the aim of this study was, evaluation of respiratory exposure to benzo (a) pyrene among asphalt workers. method: in this study, 42 samples were collected from breathi...