Halogenated-2-pyrones in Sonogashira cross-coupling: limitations, optimisation and consequences for GC analysis of Pd-mediated reactions
…, FEM Loe-Mie, EH Niemelä, CT O'Brien, AC Whitwood
文献索引:Fairlamb, Ian J. S.; Lee, Adam F.; Loe-Mie, Faidjiba E. M.; Niemelae, Elina H.; O'Brien, Ciara T.; Whitwood, Adrian C. Tetrahedron, 2005 , vol. 61, # 41 p. 9827 - 9838
The Sonogashira couplings of 4-bromo-6-methyl-2-pyrone () with phenylacetylene, mediated by Pd (PPh3) 2Cl2 in the presence of a CuI co-catalyst, have been investigated in detail. The concentration of Pd dramatically influences the product yield, with lower Pd- loadings favouring higher conversions and purer cross-coupled product. A post reaction time-dependence in product conversion is seen in samples quenched solely on silica-gel ...