Extending the Substrate Scope of Bicyclic P‐Oxazoline/Thiazole Ligands for Ir‐Catalyzed Hydrogenation of Unfunctionalized Olefins by Introducing a Biaryl Phosphoroamidite Group. Issue 8 (7th January 2015)

• Record Type: Journal Article
• Authors: Biosca, Maria; Paptchikhine, Alexander; Pàmies, Oscar; Andersson, Pher G.; Diéguez, Montserrat
• Is Part Of: Chemistry. Volume 21:Issue 8(2015)
• Page Start: 3455
• Page End: 3464
• Publication Date: 2015-01-07
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201405361
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>This study identifies a series of Ir‐bicyclic phosphoroamidite–oxazoline/thiazole catalytic systems that can hydrogenate a wide range of minimally functionalized olefins (including <italic>E</italic>‐ and <italic>Z</italic>‐tri‐ and disubstituted substrates, vinylsilanes, enol phosphinates, tri‐ and disubstituted alkenylboronic esters, and α, β‐unsaturated enones) in high enantioselectivities (<italic>ee</italic> values up to 99 %) and conversions. The design of the new phosphoroamidite–oxazoline/thiazole ligands derives from a previous successful generation of bicyclic <italic>N</italic>‐phosphane–oxazoline/thiazole ligands, by replacing the <italic>N</italic>‐phosphane group with a π‐acceptor biaryl phosphoroamidite moiety. A small but structurally important family of Ir‐phosphoroamidite–oxazoline/thiazole precatalysts has thus been synthesized by changing the nature of the N‐donor group (either oxazoline or thiazole) and the configuration at the biaryl phosphoroamidite moiety. The substitution of the <italic>N</italic>‐phosphane by a phosphoroamidite group in the bicyclic <italic>N</italic>‐phosphane–oxazoline/thiazole ligands extended the range of olefins that can be successfully hydrogenated.</p> </abstract>