- Amide-directed hydrocarbonylation of N-alkenylamides and α-alkenyllactams
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The amide-directed Rh-catalyzed hydroformylation and Pd-catalyzed hydroesterification of N-allylamides give the iso-aldehyde and ester, respectively, with good regioselectivity.The Rh- and Co2Rh2(CO)12-catalyzed reactions of N-methallylamide give an 1-acyl-2-formylpyrrolidine through a novel double carbonylation and an 1-acylpyrrolidine through reductive annulation, respectively, with excellent selectivity.A cyclic hemiamidal, N-benzoyl-2-hydroxy-4-methylpyrrolidine, the key intermediate for the double carbonylation and the reductive annulation, is obtained selectively in a Rh4(CO)12-catalyzed reaction of N-methallylamide.The hydrocarbonylations of this cyclic hemiamidal catalyzed by RhCl(PPh3)3, Co2Rh2(CO)12, and Co2(CO)8 give the corresponding double carbonylation product (2-formylpyrrolidine), reductive annulation product (pyrrolidine), and amidocarbonylation product (proline), respectively, in excellent yield and selectivity.The mechanisms of the novel double carbonylation and the reductive annulation is studied on the basis of deuterium-labeling experiments, and it is found that these reactions proceed via enamide intermediate followed by extremely regioseletive metal hydride addition to the enamide.The Rh-catalyzed hydrocarbonylations of the α-methallyl-γ- and δ-lactams in triethyl orthoformate followed by treatment with TFA give the corresponding 1-azabicycloalkenones via bicyclic hemiamidals through annulation in excellent overall yields.The Co2Rh2(CO)12-catalyzed reactions of these α-methallyl lactams give the corresponding 1-azabicycloalkanones as the sole isolable products in high yields.The RhCl(PPh3)3-catalyzed hydrocarbonylation of 6-allylpiperidin-2-one givesa mixture of 1-azabicyclo and 1-azabicyclo products.However, the addition of phosphines to the Rh catalyst remarkably improves the normal selectivity (n/iso = 9) to give 1-azabicyclodec-2-en-10-one as the predominant product.
- Ojima, Iwao,Zhang, Zhaoda
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- A general platinum-catalyzed alkoxycarbonylation of olefins
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Hydroxy- and alkoxycarbonylation reactions constitute important industrial processes in homogeneous catalysis. Nowadays, palladium complexes constitute state-of-the-art catalysts for these transformations. Herein, we report the first efficient platinum-catalysed alkoxycarbonylations of olefins including sterically hindered and functionalized ones. This atom-efficient catalytic transformation provides straightforward access to a variety of valuable esters in good to excellent yields and often with high selectivities. In kinetic experiments the activities of Pd- and Pt-based catalysts were compared. Even at low catalyst loading, Pt shows high catalytic activity.
- Beller, Matthias,Dühren, Ricarda,Franke, Robert,Ge, Yao,Huang, Weiheng,Jackstell, Ralf,Liu, Jiawang,Neumann, Helfried,Schneider, Carolin,Yang, Ji
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supporting information
p. 5235 - 5238
(2020/07/30)
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- Novel Amide-Directed Hydrocarbonylation and Double Carbonylation of N-Allylamides
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The rhodium-catalyzed hydroformylation and palladium-catalyzed hydroesteryfication of N-allylamides give isoaldehyde (1) and isoester (5), respectively, with good regioselectivity through chelation control while the rhodium- and Co2Rh2(CO)12-catalyzed reactions of an N-methallylamide give a novel double carbonylation product (10) and a pyrrolidine (11), respectively, with exellent selectivity.
- Ojima, Iwao,Zhang, Zhaoda
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p. 4422 - 4425
(2007/10/02)
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