3 research outputs found
Activation and discovery of earth-abundant metal catalysts using sodium tert-butoxide
First-row, earth-abundant metals offer an inexpensive and sustainable alternative to precious-metal catalysts. As such, iron and cobalt catalysts have garnered interest as replacements for alkene and alkyne hydrofunctionalization reactions. However, these have required the use of air- and moisture-sensitive catalysts and reagents, limiting both adoption by the non-expert as well as applicability, particularly in industrial settings. Here, we report a simple method for the use of earth-abundant metal catalysts by general activation with sodium tert-butoxide. Using only robust air- and moisture-stable reagents and pre-catalysts, both known and, significantly, novel catalytic activities have been successfully achieved, covering hydrosilylation, hydroboration, hydrovinylation, hydrogenation and [2Ï€+2Ï€] alkene cycloaddition. This activation method allows for the easy use of earth-abundant metals, including iron, cobalt, nickel and manganese, and represents a generic platform for the discovery and application of non-precious metal catalysis
Intronic features that determine the selection of the 3′ splice site
Most eukaryotic primary transcripts include segments, or introns, that will be accurately removed during RNA biogenesis. This process, known as pre-messenger RNA splicing, is catalyzed by the spliceosome, accurately selecting a set of intronic marks from others apparently equivalent. This identification is critical, as incorrectly spliced RNAs can be toxic for the organism. One of these marks, the dinucleotide AG, signals the intronic 3′ end, or 3′ splice site (ss). In this review we will focus on those intronic features that have an impact on 3′ ss selection. These include the location and type of neighboring sequences, and their distance to the 3′ end. We will see that their interplay is needed to select the right intronic end, and that this can be modulated by additional intronic elements that contribute to alternative splicing, whereby diverse RNAs can be generated from identical precursors. This complexity, still poorly understood, is fundamental for the accuracy of gene expression. In addition, a clear knowledge of 3′ ss selection is needed to fully decipher the coding potential of genomes. © 2012 John Wiley & Sons, Ltd.Work in JV's laboratory is supported by the Spanish Ministry of Science (BIO2008-01091 and 2011-25697) and CSIC (200920I195).Peer Reviewe