A bifunctional 3d‐metal catalyst for the cascade synthesis of diverse pyrroles from nitroarenes is presented. Enzymes have evolved to use abundant metals such as iron, cobalt, and nickel for redox catalysis. The following discussion will be divided according to the catalytically active metal and the ligands/co-catalysts employed. To test a more well‐defined catalyst material, Co/NGr‐C@SiO2 was washed with 2 m hydrochloric acid to remove the cobalt oxide phase and large unprotected cobalt particles, leaving only small cobalt‐containing particles protected by graphitic structures (Figures S1, S2).28 This modified material Co/NGr‐C@SiO2‐L (L=leached), obtained after selective leaching, was more active despite the lower catalyst loading (1.8 mol % Co) (entry 2). Next, we explored the applicability of Co/NGr‐C@SiO2‐L in the synthesis of pyrroles from various nitroarenes, including substrates with sensitive functional groups (Scheme 2). For an initial catalyst testing, different M/N/C nanoparticles on silica and carbon (M=Co, Fe, Ni, Mn) were selected and used for 18 h at 120 °C. Reaction conditions: 0.5 mmol nitroarene, 40 mg catalyst, 40 bar H2, 120 °C, 24 hours; 0.8 mL DMTHF or 0.8 mL 2,5‐hexanedione. 1-Substituted 1-pyrrolines were obtained in excellent yields by hydroamination–cyclization of 1-amino-4-pentyne derivatives with a mixed catalyst containing silicon and samarium <1996JA9295>. For an initial catalyst testing, different M/N/C nanoparticles on silica and carbon (M=Co, Fe, Ni, Mn) were selected and used for 18 h at 120 °C. Next, 53 was converted into the corresponding pyrrole 54 under WGSR conditions using our cobalt catalyst, providing 1.14 g 54 in 52 % yield. In the presence of this material, (transfer) hydrogenation of easily available nitroarenes and subsequent Paal–Knorr/Clauson‐Kass condensation provides >40 pyrroles in good to high yields using dihydrogen, formic acid, or a CO/H2O mixture (WGSR conditions) as reductant. Finally, we prepared (+)‐Isamoltane (CGP 361A) in four steps starting from commercially available materials (Scheme 5). Finally, we prepared (+)‐Isamoltane (CGP 361A) in four steps starting from commercially available materials (Scheme 5). A bifunctional 3d‐metal catalyst for the cascade synthesis of diverse pyrroles from nitroarenes is presented. As an example, the enantioselective synthesis of (+)‐Isamoltane is reported. Similarly, a recently reported nickel silicide9 catalyst (Ni‐Si/NiO‐SiO2@SiO2) did not give the desired pyrrole 2 with any reasonable yield (entry 7). The Friedel–Crafts alkylation of 2,4-dimethylpyrrole was achieved in 81% yield (119) using catalytic amounts of Fiaud's acid (trans-1-hydroxy-2,5-diphenylphospholane 1-oxide). Due to the intrinsic advantages, interesting developments applying homogeneous organometallic complexes or organo‐catalysts have been achieved.3, 4 On the other hand, heterogeneous catalytic materials are scarcely known in this area despite their advantageous recyclability, separation, and stability.5, 6, In the past decade, significant progress in base‐metal catalysis for redox transformations has been observed.7 In particular, metal‐nitrogen‐carbon (3d‐M/N/C) catalysts prepared by pyrolysis of supported molecularly‐defined complexes or immobilized MOFs have been widely applied for organic transformations and energy storage applications. The dominance of 1-nitropyrene and the isomer distributions of the nitropyrenes and nitrofluoranthenes observed in diesel exhaust are generally consistent with the higher reactivity of pyrene on the electrophilic reactivity scale (Nielsen, 1984; see Table 10.30) and with the Ruehle et al. Certainly these studies warrant further investigation into the use of ARMs with multivalent displays in more complex in vivo settings. This acceleration effect, however, is not specific to cobalt metal. Copyright © 2020 Elsevier B.V. or its licensors or contributors. Utilization of hydrogen as an alternative reductant gave better results (73 %). Dr. Dario Formenti, Johannes Fessler for valuable discussions and David K. Leonard (all at LIKAT) for his help in the preparation of this article. A type Ie copper-catalyzed amination leading to β-carbolin-1-ones was reported <05OBC911>. Although this novel pyrrole synthesis proved to be chemoselective in the presence of sensitive functional groups—such as halogens (20, 25), olefins (24), carbonyl compounds (23, 26) and N‐heterocycles (27)—certain limitations could be identified. When piperazine substrate 43 was tested under the optimized reaction conditions, the hydrogenation of nitro group and subsequent pyrrole formation proceeded smoothly. Editors: As an example, the enantioselective synthesis of (+)‐Isamoltane is reported. Notably, the role of cobalt nanoparticles in Co/NGr‐C@SiO2‐L in the second step of the cascade reaction is diminished and the Clauson‐Kaas condensation of anilines to form pyrroles is mainly driven by the acidic nature of the SiO2 support (Table S3). The general synthetic utility of this methodology was demonstrated on a variety of functionalized substrates including the preparation of biologically active and pharmaceutically relevant compounds, for example, (+)‐Isamoltane. Nitroarenes bearing electron‐rich substituents are well‐tolerated under standard reaction conditions, as shown with pyrroles 7 and 8. The latter was elaborated into (±)-cis-trikentrin B 97. In general, the M/NGr‐C@support catalysts were prepared starting from simple metal salts and 1,10‐phenanthroline was used as a nitrogen‐containing ligand and graphene precursor (Scheme 1 B). The alcohol oxidation, nitro reduction, and imine reduction were realized in a cascade (Scheme 7.1). Using polystyrene (PS) resins as solid supports for Au nanoparticles (AuNPs), polystyrene-supported Au nanoparticles (AuNPs@PS) were synthesized and characterized. Thus, in the desired catalytic material, metal nanoparticles should be located on an acidic support. The directly utilize nitroarenes in synthetically valuable C−N bond formation is of great significance, because the pre‐reduction step to corresponding amines can be avoided. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. Working off-campus? 2, 3), whereas other systems are only able to catalyze the latter reactions and fail to promote the reaction in the absence of protic reagents. Our robust catalyst can be used up to ten times without significant loss of activity. These active species can be commonly generated in the presence of various benign reducing agents (Figure 2). also reported the synthesis of secondary amines from various nitroarenes and primary alcohols catalyzed by a phosphine-amine ruthenium(ΙΙ) complex.7 Interestingly, the yields of amine compounds increased as the reaction proceeded under ambient pressure of molecular hydrogen (Table 7.1). (1990), Westerholm et al. Fig. Next, 53 was converted into the corresponding pyrrole 54 under WGSR conditions using our cobalt catalyst, providing 1.14 g 54 in 52 % yield. For example, secondary amines can be synthesized with good yields with Ru (acac)3/dppe/KHCO3 as catalyst.5. The electrophilic driving force of the cyclizations means that they are not regarded as exceptions to Baldwin’s rules of ring closure. This alternative protocol uses formic acid, which is readily available from bio‐waste and does not require any special experimental setup, such as high‐pressure autoclaves.