N-Alkylation of poor nucleophilic amines and derivatives with alcohols by a hydrogen autotransfer process catalyzed by copper(II) acetate: scope and mechanistic considerations

Catalytic N-Alkylation of (Hetero)Aromatic Amines and Tandem Annulation Reactions

A general and practical approach for N-alkylation of heteroaromatic amines with heteroaromatic alcohols is always challenging and rarely reported. Here, we designed and synthesized phosphine-free, robust, and efficient N,N-bidentate-Co(II) complexes for a universal N-alkylation of amines strategy. This present catalytic methodology can be applied to a wide range of substrates by varying alcohols, including aryl, aliphatic, acyclic, and cyclic groups, with heteroaromatic amines such as aminopyridine, 2-aminopyrimidine, and aminoquinoline to provide diverse monoalkylated organonitrogen compounds in good to excellent yields (108 examples). In addition, the utility of the developed catalytic protocol was also extended successfully for the dehydrogenative synthesis of biologically important quinoline derivatives (11 examples). Particularly, 8-aminoquinoline reacted differently with tandem N-alkylated-transfer hydrogenative byproduct (N-benzyl-1,2,3,4-tetrahydroquinolin-8-amine) was obtained, revealing the catalytic activity of the complex I. The reaction proceeded under environmentally benign conditions, which liberates water as the sole byproduct. Notably, a concise synthesis of acetylcholinesterase inhibitors (AChEIs) scaffolds as potential cognition enhancers illustrated the utility of the present protocol. Interestingly, various control and deuterium-labeled experiments were performed, suggesting that the reaction proceeds via the borrowing hydrogen pathway.

Visible light-induced photoredox catalyzed C-N coupling of amides with alcohols

A visible-light-mediated method for the construction of N-monoalkylated products from easily available benzamides and benzyl alcohol in the presence of eosin Y has been developed. The reaction proceeded smoothly, for a wide range of derivatives of benzamides and benzyl alcohols, to give the desired products in good to excellent yields. Biological studies, such as those on drug-likeness and molecular docking, are carried out on the molecules.

In Silico Design, Synthesis, and Biological Evaluation of Anticancer Arylsulfonamide Endowed with Anti-Telomerase Activity

Telomerase, a reverse transcriptase enzyme involved in DNA synthesis, has a tangible role in tumor progression. Several studies have evidenced telomerase as a promising target for developing cancer therapeutics. The main reason is due to the overexpression of telomerase in cancer cells (85–90%) compared with normal cells where it is almost unexpressed. In this paper, we used a structure-based approach to design potential inhibitors of the telomerase active site. The MYSHAPE (Molecular dYnamics SHared PharmacophorE) approach and docking were used to screen an in-house library of 126 arylsulfonamide derivatives. Promising compounds were synthesized using classical and green methods. Compound 2C revealed an interesting IC₅₀ (33 ± 4 µM) against the K-562 cell line compared with the known telomerase inhibitor BIBR1532 IC₅₀ (208 ± 11 µM) with an SI ~10 compared to the BALB/3-T3 cell line. A 100 ns MD simulation of 2C in the telomerase active site evidenced Phe494 as the key residue as well as in BIBR1532. Each moiety of compound 2C was involved in key interactions with some residues of the active site: Arg557, Ile550, and Gly553. Compound 2C, as an arylsulfonamide derivative, is an interesting hit compound that deserves further investigation in terms of optimization of its structure to obtain more active telomerase inhibitors

A heteroditopic NHC and phosphine ligand supported ruthenium(ii)-complex: an effective catalyst for the N-alkylation of amides using alcohols

A heteroditopic Ru(ii)-bis-NHC complex in combination with dppe was developed as an effective catalyst system (0.2 mol% loading) for the N-alkylation of amides and selective mono-/di-alkylation of 4-aminobenzamide derivatives in excellent yields.

Vanadium-doped molybdenum carbides as a promising catalyst for C–N/C–C coupling reactions

Vanadium-doped molybdenum carbides encapsulated in nitrogen-doped carbon exhibit significantly enhanced catalytic efficiency for both the oxidative C–N coupling of amines and C–C bond couplings of alcohols and ketones.

A practical method for N-alkylation of phosphinic (thio)amides with alcohols via transfer hydrogenation

This manuscript describes a modular method for preparing N-alkyl phosphinic amides from primary or secondary alcohols and primary phosphinic amide (R¹R²P=ONH₂) nucleophiles via transfer hydrogenation. The transformation typically proceeds in excellent yields, employs conveniently available reagents, and produces water as the only byproduct.

Acceptorless dehydrogenative construction of CN and CC bonds through catalytic aza-Wittig and Wittig reactions in the presence of an air-stable ruthenium pincer complex

Acceptorless dehydrogenative construction of CN and CC bonds catalysed by air-stable ruthenium complexes.

N-Alkyl amide synthesis via N-alkylation of amides with alcohols

The present review summarizes the recent development of N-alkylation of amides with alcohols according to the classification of catalysts.

Valorization of Biomass Derived Terpene Compounds by Catalytic Amination

This review fills an apparent gap existing in the literature by providing an overview of the readily available terpenes and existing catalytic protocols for preparation of terpene-derived amines. To address the role of solid catalysts in amination of terpenes the same reactions with homogeneous counterparts are also discussed. Such catalysts can be considered as a benchmark, which solid catalysts should match. Although catalytic systems based on transition metal complexes have been developed for synthesis of amines to a larger extent, there is an apparent need to reduce the production costs. Subsequently, homogenous systems based on cheaper metals operating by nucleophilic substitution (e.g., Ni, Co, Cu, Fe) with a possibility of easy recycling, as well as metal nanoparticles (e.g., Pd, Au) supported on amphoteric oxides should be developed. These catalysts will allow synthesis of amine derivatives of terpenes which have a broad range of applications as specialty chemicals (e.g., pesticides, surfactants, etc.) and pharmaceuticals. The review will be useful in selection and design of appropriate solid materials with tailored properties as efficient catalysts for amination of terpenes.

N-Monomethylation of Aromatic Amines with Methanol via PNHP-Pincer Ru Catalysts

The use of methanol for the selective methylation of aromatic amines with RuHCl(CO)(PN^HP) (PN^HP = bis(2-diphenylphosphinoethyl)amine) is reported. Various aromatic amines were transformed into their corresponding monomethylated secondary amines in high yields at 150 °C with a very low catalyst loading (0.02-0.1 mol %) in the presence of KO ^tBu (20-60 mol %). The catalyst precursor, RuHCl(CO)(PN^HP), was converted to [RuH(CO)₂(PN^HP)]⁺ under the catalytic conditions and also serves as a highly effective catalyst. The robustness of this catalyst contributes to its outstanding catalytic activity, even under reaction conditions, in which CO is liberated from methanol.

A Two-Step Procedure for the Overall Transamidation of 8-Aminoquinoline Amides Proceeding via the Intermediate N-Acyl-Boc-Carbamates

Herein a two-step strategy for achieving overall transamidation of 8-aminoquinoline amides has been explored. In this protocol, the 8-aminoquinoline amides were first treated with Boc₂O and DMAP to form the corresponding N-acyl-Boc-carbamates, which were found to be sufficiently reactive to undergo subsequent aminolysis with different amines in the absence of any additional reagents or catalysts. To demonstrate the utility of this approach, it was applied on a number of 8-aminoquinoline amides from the recent C-H functionalization literature, enabling access to a range of elaborate amide derivatives in good to high yields.

Nickel-Catalyzed Phosphine Free Direct N-Alkylation of Amides with Alcohols

Herein, we developed an operational simple, practical, and selective Ni-catalyzed synthesis of secondary amides. Application of renewable alcohols, earth-abundant and nonprecious nickel catalyst facilitates the transformations, releasing water as byproduct. The catalytic system is tolerant to a variety of functional groups including nitrile, allylic ether, and alkene and could be extended to the synthesis of bis-amide, antiemetic drug Tigan, and dopamine D2 receptor antagonist Itopride. Preliminary mechanistic studies revealed the participation of a benzylic C-H bond in the rate-determining step.

Hydrogen autotransfer and related dehydrogenative coupling reactions using a rhenium(i) pincer catalyst

A novel rhenium complex bearing a non-innocent PNP pincer ligand was prepared.

Pd@[nBu₄][Br] as a Simple Catalytic System for N-Alkylation Reactions with Alcohols

Palladium nanoparticles, simply and briefly generated in commercial and cheap onium salts using supercritical carbon dioxide, have been found to be an effective catalytic system for additive free N-alkylation reaction using alcohols via cascade oxidation/condensation/reduction steps.

Sucrose and KF quenching system for solution phase parallel synthesis

The KF, sucrose (table sugar) exploited as quenching system in solution phase parallel synthesis. Excess of electrophiles were covalently trapped with hydroxyl functionality of sucrose and due to polar nature of sucrose derivative was solubilize in water. Potassium fluoride used to convert various excess electrophilic reagents such as acid chlorides, sulfonyl chlorides, isocyanates to corresponding fluorides, which are less susceptible for hydrolysis and subsequently sucrose traps these fluorides and dissolves them in water thus removing them from reaction mixture. Various excess electrophilic reagents such as acid chlorides, sulfonyl chlorides, and isocyanates were quenched successfully to give pure products in excellent yields.

Synthesis of 1,3,5-triazines via Cu(OAc)2-catalyzed aerobic oxidative coupling of alcohols and amidine hydrochlorides

Cu(OAc)2 was found to be an efficient catalyst for dehydrogenative synthesis of 1,3,5-triazine derivatives via oxidative coupling reaction of amidine hydrochlorides and alcohols in air. Both aromatic and aliphatic alcohols can be involved in the reaction and thirty-three products were obtained with good to excellent yields. Moreover, the use of a ligand, strong base and organic oxidant is unnecessary.

A Step into an eco-Compatible Future: Iron- and Cobalt-catalyzed Borrowing Hydrogen Transformation

Living on borrowed hydrogen: Recent developments in iron- and cobalt-catalyzed borrowing hydrogen have shown that economically reliable catalysts can be used in this type of waste-free reactions. By using well-defined inexpensive catalysts, known reactions can now be run efficiently without the necessary use of noble metals; however, in addition new types of reactivity can also be discovered.

DFT study on the iridium-catalyzed multi-alkylation of alcohol with ammonia

The catalytic mechanism for the multi-alkylation of benzyl alcohols with ammonia catalyzed by the water-soluble catalyst, [Cp*Ir^III(NH₃)₃][I]₂, is computationally investigated by density functional theory (DFT).