کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1335847 | 979556 | 2016 | 6 صفحه PDF | دانلود رایگان |
A kinetic analysis of the hydroboration of iso-quinoline with pinacol borane (HBpin) and catalysed by a β-diketiminato magnesium n-butyl pre-catalyst has provided evidence that the reaction proceeds via rate determining Mg–N/H–B metathesis of a dearomatised iso-quinolide anion. The reaction rate is suppressed by increasing [iso-quinoline] leading to the suggestion that catalytic turnover is also dependent on a pre-equilibrium involving dissociation of donor substrate molecules from the coordination sphere of the catalytic Mg centre. Stoichiometric reactions with a variety of poly-pyridine heterocycles have provided a range of magnesium derivatives of the dearomatised poly-pyridides either by alkyl or hydride transfer. The resistance of these latter species toward hydroboration is rationalised as a consequence of their additional coordinative stability providing corroborative evidence for the dissociative mechanism inferred from the kinetic analysis.
Kinetic analysis of the Mg-catalysed hydroboration of iso-quinoline with pinacol borane (HBpin) and studies of poly-pyridine dearomatisation, which are resistant to the hydroboration catalysis, have provided evidence that the catalysis proceeds via rate determining Mg–N/H–B metathesis of dearomatised pyridide anions.Figure optionsDownload as PowerPoint slide
Journal: Polyhedron - Volume 103, Part A, 8 January 2016, Pages 115–120