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1.
J Org Chem ; 81(3): 787-802, 2016 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-26735748

RESUMEN

We report the first example of a very general Cu-catalyzed cross-coupling of organoaluminum reagents with organohalides. The reactions proceed for the couplings of alkyl-, aryl-, and alkynylaluminum reagents with aryl and heteroaryl halides and vinyl bromides, affording the cross-coupled products in good to excellent yields. Both primary and secondary alkylaluminum reagents can be utilized as organometallic coupling partners. These reactions are not complicated by ß-hydride elimination, and as a result rearranged products are not observed with secondary alkylaluminum reagents even for couplings with heteroaryl halides under "ligand-free" conditions. Radical clock experiment with a radical probe and relative reactivity study of Ph3Al with two haloarenes, 1-bromonaphthalene and 4-chlorobenzonitrile, having two different redox potentials indicates that the reaction does not involve free aryl radicals and radical anions as intermediates. These results combined with the result of the Hammett plot obtained by reacting Ph3Al with iodoarenes containing p-H, p-Me, p-F, and p-CF3 substituents, which shows a linear curve (R(2) = 0.99) with a ρ value of +1.06, suggest that the current transformation follows an oxidative addition-reductive elimination pathway.

2.
Sci Rep ; 10(1): 15214, 2020 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-32939017

RESUMEN

In order to better understand the spatial spread of bovine tuberculosis (bTB) in Wales, an All Wales Badgers Found Dead (AWBFD) survey was carried out from 2014-2016. For Wales, as a whole, there was a significant decrease (p < 0.001) in prevalence of bTB in badgers since a similar survey was carried out in 2005-2006, with a drop from 13.3% to 7.3%. The highest prevalence was observed for the High TB Area East (18.6%), which shares its border with England, and differed significantly (p < 0.001) from the High TB Area West (7.4%). The lowest proportion of carcases diagnosed with the disease (0.7%) was in the Low TB Area, followed by the two Intermediate TB Areas of Wales (2.7%). The M. bovis isolates from badgers tended to be similar to the genotypes of cattle in the same area, except in the Low TB Area. The direction of any cross species transmission and the drivers for this cannot be determined from this study. The spatial variations described here support the need for regionally adapted surveillance and control measures for bovine tuberculosis in Wales.


Asunto(s)
Mustelidae/microbiología , Mycobacterium bovis/aislamiento & purificación , Tuberculosis/epidemiología , Animales , Femenino , Masculino , Vigilancia de la Población , Prevalencia , Análisis Espacio-Temporal , Tuberculosis/veterinaria , Gales/epidemiología
3.
Org Lett ; 22(8): 3268-3272, 2020 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-32237752

RESUMEN

We describe a novel method to synthesize 2,5-dialkyl-4,6,7-tricyanoindole derivatives from a base-catalyzed reaction of 1,3-diketones with fumaronitrile. The reaction proceeds by the condensation of two molecules of fumaronitrile and one molecule of 1,3-diketone in a remarkable process that involves the cleavage of one C(sp3)-C(sp2) bond in 1,3-diketones and the formation of one carbon-nitrogen bond and four carbon-carbon bonds to construct both the aryl and pyrrole rings of the indole in one step.

4.
Vet Rec ; 183(23): 717, 2018 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-30487295

RESUMEN

Extending on earlier work, trends in bovine tuberculosis (bTB) from 2003 to 2015 are described for the countries of the UK and the Republic of Ireland using standardised definitions and measures. Based on measures of animal and herd incidence, there remains a stable situation of extremely low prevalence in Scotland and the Low Risk Area of England, and a higher but ongoing reduction in prevalence in the Republic of Ireland. In Northern Ireland, there has been a rising bTB trend during 2010-2015, although not to levels experienced during 2002-2004. In the High Risk Area and Edge Area of England during 2010-2015, the rising bTB trends have continued but with some recent evidence of stabilisation. In Wales, prevalence has fallen subsequent to a peak in 2008. The paper considers country-level differences in the light of key policy changes, which are presented in detail. This work is unique, and will assist policymakers when critically evaluating policy options for effective control and eradication. Ongoing updates of this analysis would be useful, providing an evidence base for country-level comparison of bTB trends into the future. The use of multivariable analytical methods should be considered, but will rely on substantial sharing of raw data across the five countries.


Asunto(s)
Tuberculosis Bovina/epidemiología , Animales , Bovinos , Incidencia , Irlanda/epidemiología , Prevalencia , Reino Unido/epidemiología
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