4. Ruthenium porphyrin catalysed direct intermolecular amino-oxyarylation of alkenes including styrenes and 1,3-dienes to give primary amines with O-(2,4-dinitrophenyl)hydroxylamine as the amine source was achieved in moderate to good yields under mild reaction conditions. Spectroscopic analyses revealed that a ruthenium nitrido complex was the key reaction intermediate for the amino-oxyarylation reaction.(https://doi.org/10.1039/C9CC08043K)
3. Transition-metal-catalyzed direct CeH bond amination is an attractive strategy in preparation of nitrogen containing molecules which are common in naturally occurring and pharmaceutically important compounds. Comparing to the precious metals commonly used in this reaction, non-precious metals such as iron are abundant in earth, relatively low toxic, and more biocompatible, which meet the increasing demand for environmentally benign and sustainable chemical processes. In this review, we described the development in iron catalyzed C-H bond amination reactions from historical landmarks to recent achievements, and placed emphasis on their applications in organic synthesis, i.e. natural product synthesis and/or modification.(https://doi.org/10.1016/j.tet.2019.130607)
2. Ruthenium(II) complexes bearing a tridentate bis(N‐heterocyclic carbene) ligand reacted with iminoiodanes (PhI=NR) resulting in the formation of isolable ruthenium(III)–amido intermediates, which underwent cleavage of a C−N bond of the tridentate ligand and formation of an N‐substituted imine group. The RuIII–amido intermediates have been characterized by 1H NMR, UV/Vis, ESI‐MS, and X‐ray crystallography. DFT calculations were performed to provide insight into the reaction mechanism.(https://doi.org/10.1002/chem.201903012)
1. Metal‐catalyzed intramolecular C−H amination of alkyl azides constitutes an appealing approach to alicyclic amines; challenges remain in broadening substrate scope, enhancing regioselectivity, and applying the method to natural product synthesis. Herein we report an iron(III) porphyrin bearing axial N‐heterocyclic carbene ligands which catalyzes the intramolecular C(sp3)–H amination of a wide variety of alkyl azides under microwave‐assisted and thermal conditions, resulting in selective amination of tertiary, benzylic, allylic, secondary, and primary C−H bonds with up to 95 % yield. 14 out of 17 substrates were cyclized selectively at C4 to give pyrrolidines. The regioselectivity at C4 or C5 could be tuned by modifying the reactivity of the C5–H bond. Mechanistic studies revealed a concerted or a fast re‐bound mechanism for the amination reaction. The reaction has been applied to the syntheses of tropane, nicotine, cis‐octahydroindole, and leelamine derivatives.(https://doi.org/10.1002/anie.201806059)
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