Bulky Phosphinines: From a Molecular Design to an Application in Homogeneous Catalysis. Issue 27 (13th May 2013)

• Record Type: Journal Article
• Authors: Weemers, Jarno J. M.; van der Graaff, Willem N. P.; Pidko, Evgeny A.; Lutz, Martin; Müller, Christian
• Is Part Of: Chemistry. Volume 19:Issue 27(2013)
• Page Start: 8991
• Page End: 9004
• Publication Date: 2013-05-13
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201300557
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The design and preparation of an asymmetrically substituted and bulky phosphinine was achieved by introducing sterically demanding substituents into specific positions of a rigid phosphorus‐heterocyclic framework. Compound <bold>5</bold> shows, at the same time, axial chirality and a sufficiently high energy barrier for internal rotation to prevent enantiomerization. Both enantiomers of <bold>5</bold> were isolated by means of chiral analytical HPLC, and their absolute configurations could be assigned by combining experimental data and DFT calculations. Despite its substitution pattern, <bold>5</bold> can still coordinate to transition‐metal centers through the lone pair of electrons on the phosphorus atom. Rapid CH activation on the adjacent aryl substituent at the 2‐position of the phosphorus heterocycle was achieved by using [{Cp*IrCl₂}₂] (Cp*=1, 2, 3, 4, 5‐pentamethylcyclopentadienyl) as a metal precursor. A racemic mixture of <bold>5</bold> was applied as a π‐accepting low‐coordinate phosphorus ligand in the Rh‐catalyzed hydroformylation of <italic>trans</italic>‐2‐octene, which showed a clear preference for the formation of 2‐methyloctanal.</p> </abstract>