The search for a low-cost process for the valorization of linear α-olefins combining high productivity and high selectivity is a longstanding goal for chemists. Herein, we report a soluble ruthenium olefin metathesis catalyst that performs the conversion of linear α-olefins to longer internal linear olefins with high selectivity (>99%) under neat conditions at low loadings (50 ppm) and without the need of expensive additives. This robust catalytic process allowed us to efficiently and selectively re-equilibrate the naphtha fraction (C5–C8) of a Fischer–Tropsch feed derived from non-petroleum resources to a higher-value product range (C9–C14), useful as detergent and plasticizer precursorsThis work was supported by the European Community through the seventh framework program (CP-FP 211468-2 EUMET, grant to M.R., L.F., and E.B.). M.M. thanks the CNRS, the ENSCR, Rennes Métropole, and the Région-Bretagne for their financial support. A.P. thanks the Spanish MINECO for project CTQ2014- 59832-JIN, and L.C. acknowledges funding from the King Abdullah University of Science and Technology (KAUST
Non-stabilized azomethine ylide 4a reacts smoothly at room temperature with a variety of uncomplexed aromatic heterocycles and carbocycles on the condition that the ring contains at least one or two electron-withdrawing substituents, respectively. Aromatic substrates, including pyridine and benzene derivatives, participate as 2π components in [3+2] cycloaddition reactions and interact with one, two, or three equivalent(s) of the ylide, depending on their structure and substitution pattern. Thus, this process affords highly functionalized polycyclic structures that contain between one and three pyrrolidinyl ring(s) in useful yields. These results indicate that the site selectivity of the cycloaddition reactions strongly depends on both the nature and the positions of the substituents. In most cases, the second 1,3-dipolar reaction occurs on the opposite face to the one that contains the first pyrrolidinyl ring. DFT calculations on model compounds indicate that a concerted mechanism features a low activation barrier.
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