Calcium Hydride Catalysts for Olefin Hydrofunctionalization: Ring‐Size Effect of Macrocyclic Ligands on Activity

Chemistry - A European Journal, vol. 27, pp. 3002–3007

Abstract

Abstract The fifteen‐membered NNNNN macrocycle Me5PACP (Me5PACP=1,4,7,10,13‐pentamethyl‐1,4,7,10,13‐pentaazacyclopentadecane) stabilized the [CaH]+ fragment as a dimer with a distorted pentagonal bipyramidal coordination geometry at calcium. The hydride complex was prepared by protonolysis of calcium dibenzyl with the conjugate acid of Me5PACP followed by hydrogenolysis or treating with nOctSiH3 of the intermediate calcium benzyl cation. The calcium hydride catalyzed the hydrogenation and hydrosilylation of unactivated olefins faster than the analogous calcium complex stabilized by the twelve‐membered NNNN macrocycle Me4TACD (Me4TACD=1,4,7,10‐tetramethyl‐1,4,7,10‐tetraazacyclododecane). Kinetic investigations indicate that higher catalytic efficiency for the Me5PACP stabilized calcium hydride is due to easier dissociation of the dimer in solution when compared to the Me4TACD analogue.

Authors 7

1. Thomas Höllerhage Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52056 Aachen Germany

2. Danny Schuhknecht Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52056 Aachen Germany

3. Alisha Mistry Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52056 Aachen Germany

4. Thomas P. Spaniol Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52056 Aachen Germany

5. Yan Yang

   Centre National de la Recherche Scientifique · Université Toulouse III - Paul Sabatier · Institut National des Sciences Appliquées de Toulouse · Laboratoire de Physique et Chimie des Nano-Objets · Université de Toulouse

   Affiliation as printed

   CNRS, INSA, UPS, UMR 5215, LPCNO Université de Toulouse 135 avenue de Rangueil 31077 Toulouse France

   Laboratoire de physique et chimie des nano-objets

6. Laurent Maron corresponding

   Centre National de la Recherche Scientifique · Université Toulouse III - Paul Sabatier · Institut National des Sciences Appliquées de Toulouse · Laboratoire de Physique et Chimie des Nano-Objets · Université de Toulouse

   Affiliation as printed

   CNRS, INSA, UPS, UMR 5215, LPCNO Université de Toulouse 135 avenue de Rangueil 31077 Toulouse France

   Laboratoire de physique et chimie des nano-objets

7. Jun Okuda corresponding Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52056 Aachen Germany