A Multicatalytic Approach to the Hydroaminomethylation of α‐Olefins. (15th February 2019)

• Record Type: Journal Article
• Authors: Hanna, Steven; Holder, Jeffrey C.; Hartwig, John F.
• Is Part Of: Angewandte Chemie. Volume 131:Number 11(2019)
• Page Start: 3406
• Page End: 3410
• Publication Date: 2019-02-15
• Subjects: Hydroaminomethylierung -- Hydroformylierung -- Multikatalyse -- Reduktive Aminierung -- Transferhydrierung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201811297
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: We report an approach to conducting the hydroaminomethylation of diverse α‐olefins with a wide range of alkyl, aryl, and heteroarylamines at relatively low temperatures (70–80 °C) and pressures (1.0–3.4 bar) of synthesis gas. This approach is based on simultaneously using two distinct catalysts that are mutually compatible. The hydroformylation step is catalyzed by a rhodium diphosphine complex, and the reductive amination step, which is conducted as a transfer hydrogenation with aqueous, buffered sodium formate as the reducing agent, is catalyzed by a cyclometallated iridium complex. By adjusting the ratio of CO to H2, we conducted the reaction at one atmosphere of gas with little change in yield. A diverse array of olefins and amines, including hetreroarylamines that do not react under more conventional conditions with a single catalyst, underwent hydroaminomethylation with this new system, and the pharmaceutical ibutilide was prepared in higher yield and under milder conditions than with a single catalyst. Abstract : Zwei spezifische, kompatible Katalysatoren ermöglichen die Hydroaminomethylierung von Alkenen mit Synthesegas bei Atmosphärendruck und nur 80 °C. Der Hydroformylierungsschritt wird durch einen Rh‐Diphosphinkomplex katalysiert. Die reduktive Aminierung, die als Transferhydrierung mit wässrigem Natriumformiat als Reduktionsmittel durchgeführt wird, erfolgt in Gegenwart eines cyclometallierten Iridiumkomplexes.