An Unprecedented Rhodium‐Catalyzed Asymmetric Intermolecular Hydroacylation Reaction with Salicylaldehydes

Abstract

An unprecedented enantio-and diastereoselective rhodium-catalyzed intermolecular hydroacylation reaction of salicylaldehydes with norbornenes is reported in which the corresponding aryl ketones are obtained in high diastereomeric and moderate enantiomeric excesses. It was found that monodentate phosphoramidite ligands gave rise to endo products, while bidentate phosphine ligands catalyzed the reaction to form exo products predominantly.

Phosphoramidite: privilegierte Liganden in der asymmetrischen Katalyse

“…[446] Die Produkte wurden in hohen Ausbeuten isoliert, aber die Enantioselektivität für die Bildung des endoProdukts 325 war niedrig. Bemerkenswerterweise entstand das als Nebenprodukt gebildete exo-Diastereomer 326 mit wesentlich höherer Enantioselektivität.…”

Intermolecular rhodium catalyzed hydroacylation of allenes: the regioselective synthesis of β,γ-unsaturated ketones

“…Importantly, the majority of products obtained from di-or trisubstituted allene hydroacylation reactions feature a stereogenic centre, therefore presenting the possibility of enantioselective catalysis. 13,20 4. Experimental section…”

Rhodium‐Catalyzed C(sp2)‐ or C(sp3)−H Bond Functionalization Assisted by Removable Directing Groups

“…Phenol is an easily obtainable functional group and presents in avariety of important structural motifs.Protection is sometimes required for the C À Hf unctionalization of phenols.A lthough af ew pioneering reports on the directed CÀHf unctionalization of free phenols have been reported, [49][50][51] the major drawback is the uncontrollability of the reaction. Therefore,t he in situ transformation or prefunctionalization of hydroxy groups is frequently carried out to control the reaction.…”