A Multicatalytic Approach to the Hydroaminomethylation of α‐Olefins. Issue 11 (15th February 2019)

• Record Type: Journal Article
• Authors: Hanna, Steven; Holder, Jeffrey C.; Hartwig, John F.
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 11(2019)
• Page Start: 3368
• Page End: 3372
• Publication Date: 2019-02-15
• Subjects: hydroaminomethylation -- hydroformylation -- multicatalytic -- reductive amination -- transfer hydrogenation; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201811297
• Languages: English
• ISSNs: 1433-7851

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 : Two cats make HAM : Two distinct, mutually compatible catalysts enable the hydroaminomethylation of alkenes at or near atmospheric pressure of syngas and just 80 °C. 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.