No abstract

In terms of its abundance and its minimal toxicity, iron has advantages relative to other transition metals. Although alkyl–alkyl bond construction is central to organic synthesis, examples of iron‐catalyzed alkyl–alkyl couplings of alkyl electrophiles are relatively sparse. Herein we report an iron catalyst that achieves cross‐coupling reactions of alkyl electrophiles wherein olefins, in the presence of a hydrosilane, are used in place of alkylmetal reagents. Carbon–carbon bond formation proceeds at room temperature, and the method employs commercially available components (Fe(OAc)2, Xantphos, and Mg(OEt)2); interestingly, this set of reagents can be applied directly to a distinct hydrofunctionalization of olefins, hydroboration. Mechanistic studies are consistent with the generation of an alkyl radical from the alkyl electrophile, as well as with reversibility for elementary steps that precede carbon–carbon bond formation (olefin binding to iron and β‐migratory insertion).

In terms of its abundance and its minimal toxicity, iron has advantages relative to other transition metals. Although alkyl–alkyl bond construction is central to organic synthesis, examples of iron‐catalyzed alkyl–alkyl couplings of alkyl electrophiles are relatively sparse. Herein we report an iron catalyst that achieves cross‐coupling reactions of alkyl electrophiles wherein olefins, in the presence of a hydrosilane, are used in place of alkylmetal reagents. Carbon–carbon bond formation proceeds at room temperature, and the method employs commercially available components (Fe(OAc)2, Xantphos, and Mg(OEt)2); interestingly, this set of reagents can be applied directly to a distinct hydrofunctionalization of olefins, hydroboration. Mechanistic studies are consistent with the generation of an alkyl radical from the alkyl electrophile, as well as with reversibility for elementary steps that precede carbon–carbon bond formation (olefin binding to iron and β‐migratory insertion).

A procedure for the evaluation of activity for industrial hydrotreating catalysts is described in detail. The evaluation of the catalyst quality and its performance is carried out on different experimental levels. The first corresponds to the analytic characterization of physical and chemical properties of the catalyst. Levels 2 and 3 correspond to the evaluation of its catalytic properties in a micro reactor and pilot plant, respectively. A comparison of the experimental results with those calculated using mathematical models constitutes the next evaluating level. With all these results we can have a preliminary diagnosis of the catalyst's quality. If data from AQ1 ORDER REPRINTS the operation of the catalyst at industrial plant are available, it is possible to make a comparison with those obtained in the different experimental levels. With all of this information it is also possible to make performance predictions in terms of activity, selectivity, and stability. The obtained results are very consistent at different levels of evaluation and allow us to establish the quality of the catalyst with great confidence.