Synthesis of azafluoranthenes by iridium-catalyzed [2 + 2 + 2] cycloaddition and evaluation of their fluorescence properties.

We report a method for the synthesis of azafluoranthenes under neutral reaction conditions in a highly atom-economical manner by the iridium-catalyzed [2 + 2 + 2] cycloaddition of 1,8-dialkynylnaphthalenes with nitriles. A variety of nitriles react with methyl- or phenyl-substituted 1,8-dialkynylnaphthalenes to give a wide range of azafluoranthenes. Azafluoranthenes bearing an amino group show intense fluorescence at around 500 nm. Comparison of the fluorescence properties of amine-substituted azafluoranthenes with related compounds revealed the importance of the amine moiety for obtaining a high fluorescence quantum yield. The choice of the solvent affected the emission maxima and the fluorescence quantum yield. Azafluoranthenes bearing pyrrolidine exhibited blue-shifted emission bands in a non-polar solvent and gave a fluorescence quantum yield of 0.76 in toluene. A Lippert-Mataga plot and computational studies provide insight into the origin of the fluorescence of azafluoranthenes. Furthermore, cellular experiments using human breast adenocarcinoma cells SK-BR-3 demonstrated the feasibility of using azafluoranthenes as fluorescent probes.

Bryophytes from a forest remnant in the campus of the Universidade Federal de São Carlos, municipality of Sorocaba, State of São Paulo, Brazil / Briófitas do remanescente florestal do campus da Universidade Federal de São Carlos, município de Sorocaba, Estado de São Paulo, Brasil

The campus of the Universidade Federal de São Carlos, in the municipality of Sorocaba, is composed of a forest remnant characterized by vegetation of seasonal semidecidual tropical forest and cerrado. We recorded 96 species of bryophytes in the area: 56 mosses (Fissidentaceae is the richest, with 11 spp.) and 40 liverworts (Lejeuneaceae is the most representative, with 21 spp.). Eight species are endemic to Brazil and two were mentioned for the first time in the State of São Paulo (Fissidens allionii Broth. and Lejeunea subsessilis Spruce). The predominance of corticolous species and mat life form indicate a strong relationship with the microclimate conditions of the environment, as well as the availability of substrate. The simultaneous presence of species from the Atlantic Forest and the Cerrado indicates an transition zone bryoflora, at the same time that subcosmopolitan and ruderal species with wide distribution express the secondary character of the forest remnant.

O campus da Universidade Federal de São Carlos do município de Sorocaba é composto por um remanescente florestal caracterizado por vegetação de mata estacional semidecidual e cerrado. Foram encontradas 96 espécies de briófitas na área: 56 musgos (sendo Fissidentaceae a família mais rica, com 11 spp.) e 40 hepáticas (sendo Lejeuneaceae a mais representativa, com 21 spp.). Oito espécies são endêmicas do Brasil e duas foram citadas pela primeira vez no Estado de São Paulo (Fissidens allionii Broth. e Lejeunea subsessilis Spruce). O predomínio de espécies corticícolas e da forma de vida em tapete indicam a forte relação com as condições microclimáticas do ambiente, assim como a disponibilidade de substrato. A presença simultânea de espécies da Mata Atlântica e do Cerrado indica uma área de transição, ao mesmo tempo que espécies de ampla distribuição, subcosmopolitas e ruderais expressam o caráter secundário do remanescente florestal.

Iridium-catalyzed C3-selective asymmetric allylation of 7-azaindoles with secondary allylic alcohols.

The development of efficient synthetic methods of 7-azaindoles has been desired due to the useful biological activities and physical properties. We report the first example of the iridium-catalyzed C3-selective asymmetric allylation of 7-azaindoles with racemic secondary allylic alcohols to give only branched allylation products in good to high yields with high enantioselectivity (up to >99.5% ee). Allylic alcohols and 7-azaindoles with a variety of functional groups including halogen and heteroaromatic groups are compatible with the reaction conditions. Furthermore, transformations of the obtained allylation products are demonstrated without a significant loss of enantiomeric excess.