Autoinduced Catalysis and Inverse Equilibrium Isotope Effect in the Frustrated Lewis Pair Catalyzed Hydrogenation of Imines. Issue 22 (15th April 2015)

• Record Type: Journal Article
• Authors: Tussing, Sebastian; Greb, Lutz; Tamke, Sergej; Schirmer, Birgitta; Muhle‐Goll, Claudia; Luy, Burkhard; Paradies, Jan
• Is Part Of: Chemistry. Volume 21:Issue 22(2015)
• Page Start: 8056
• Page End: 8059
• Publication Date: 2015-04-15
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201500805
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The frustrated Lewis pair (FLP)‐catalyzed hydrogenation and deuteration of <italic>N‐</italic>benzylidene‐<italic>tert‐</italic>butylamine (<bold>2</bold>) was kinetically investigated by using the three boranes B(C₆F₅)₃ (<bold>1</bold>), B(2, 4, 6‐F₃‐C₆H₂)₃ (<bold>4</bold>), and B(2, 6‐F₂‐C₆H₃)₃ (<bold>5</bold>) and the free activation energies for the H₂ activation by FLP were determined. Reactions catalyzed by the weaker Lewis acids <bold>4</bold> and <bold>5</bold> displayed autoinductive catalysis arising from a higher free activation energy (2 kcal mol⁻¹) for the H₂ activation by the imine compared to the amine. Surprisingly, the imine reduction using D₂ proceeded with higher rates. This phenomenon is unprecedented for FLP and resulted from a primary inverse equilibrium isotope effect.</p> </abstract>