Recent advances in electrochemical copper catalysis for modern organic synthesis

• Yemin Kim and
• Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

• enantioenriched nitrile products 89 and a reduced Cu(I) complex 94, which is reoxidized through anodic oxidation. The 1,2-diamine moiety is present in numerous natural products and bioactive compounds. In 2022, Xu et al. reported the Cu-catalyzed electrocatalytic diazidation of olefins with ppm-level catalyst

• loading, providing an alternative strategy for 1,2-diamine synthesis (Figure 16) [71]. This reaction successfully expanded the substrate scope from electron-rich to electron-deficient alkenes, which were considered challenging substrates in previous diazidation reactions. A possible mechanism is proposed

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• [12][13][16][19][26]. 1H derivatives can be obtained in a number of ways, including direct condensation of N,N'-dimethylphenylene-1,2-diamine derivatives with the appropriate aldehydes, YCHO [24][27], or borohydride reduction of 1+ salts [24]. The cations conversely can be obtained from 1H derivatives

• , for example through hydride abstraction by Ph3C+ [13]. Alternatively, they can also be obtained by condensation of N,N'-dimethylphenylene-1,2-diamine derivatives with acid chlorides, YCOCl, or through the methylation of 2-substituted benzoimidazoles [24], which in turn can be obtained from

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• with Fe2(CO)9 as a catalyst and N1,N1,N2,N2-tetramethylethane-1,2-diamine (TMEDA) as bidentate ligand. A gram-scale alkylation reaction showed that the new procedure has excellent potential for synthetic applications. The mechanism study shows that radicals are the starting point of the coupling

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• much cheaper than diphenyl(2-(triethoxysilyl)ethyl)phosphine. With this setup, the flow system consisted of two mixtures: a mixture A containing furfural (0.7 M) and 2-(piperidin-1-yl)ethane-1,2-diamine (0.7 M) and a mixture B containing vinyltriethoxysilane (1.05 or 2.1 M) and the ruthenium catalyst

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• context, Bai and co-workers (2019) developed the direct intermolecular enantioselective C–H amination of N-aryl-2-naphthylamines 92 with azodicarboxylates 93 to prepare N–C atropisomers of nonbiaryl naphthalene-1,2-diamine 94. In the presence of chiral phosphoric acids (CPA 15), the desired product 94 was

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• ]diazepines 26 using substituted 2-formylbenzoic acids 25, phenylenediamine and tetronic acid with water as solvent (Scheme 8). The mechanism leading to the formation of the final product 24 and 26 involves an initial condensation between tetronic acid and benzene-1,2-diamine to give enaminone A. An

Au(III) complexes with tetradentate-cyclam-based ligands

• Ann Christin Reiersølmoen,
• Thomas N. Solvi and
• Anne Fiksdahl

Beilstein J. Org. Chem. 2021, 17, 186–192, doi:10.3762/bjoc.17.18

• in two model reactions. Results and Discussion Synthesis of potential ligands Chiral cyclam derivatives have previously been directly synthesized from (1R,2R)-cyclohexane-1,2-diamine (A) and malonyl dichloride [36], giving 36% yield of the wanted cyclam tetraamide product 2a. Additionally, a

Synthesis of novel fluorinated building blocks via halofluorination and related reactions

• Attila Márió Remete,
• Tamás T. Novák,
• Melinda Nonn,
• Matti Haukka,
• Ferenc Fülöp and
• Loránd Kiss

Beilstein J. Org. Chem. 2020, 16, 2562–2575, doi:10.3762/bjoc.16.208

• trans-4-cyclohexene-1,2-diamine dihydrochloride and 1,1’-carbonyldiimidazole (CDI), through a slightly modified literature protocol [36], the desired product was isolated in only 10% yield (Scheme 7). Increasing the reaction temperature considerably decreased the product purity. With the low yield in

Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

• Shrikant D. Tambe,
• Kwan Hong Min,
• Naeem Iqbal and
• Eun Jin Cho

Beilstein J. Org. Chem. 2020, 16, 1335–1342, doi:10.3762/bjoc.16.114

• . The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis. Keywords: 1,2-diamine; diversity; imine; photocatalysis; visible light; Introduction The selective formation of distinct valuable compounds from the

• photocatalytic synthetic methods are mainly limited to aniline-based substrates and do not encompass aliphatic amines. We planned the synthesis of 1,2-diamine compounds having an aliphatic amine moiety by the intermolecular coupling of N-benzylidines with aliphatic amines that not only act as coupling partner

• hypothesized that the structural modification of the substrate might affect its reactivity, and to our delight, the introduction of an ortho-phenyl moiety on the N-benzylideneaniline species provided the desired 1,2-diamine product, wherein the N,N-dicyclohexylmethylamine (Cy2NMe) acted as both the coupling

Towards the total synthesis of chondrochloren A: synthesis of the (Z)-enamide fragment

• Jan Geldsetzer and
• Markus Kalesse

Beilstein J. Org. Chem. 2020, 16, 670–673, doi:10.3762/bjoc.16.64

• ′-dimethylethane-1,2-diamine. Keywords: cross coupling; myxobacteria; natural product; ribolactone; Z-enamide; Introduction In the course of our program to provide synthetic access to biologically active natural products we targeted complex polyketides and depsipetides [1][2][3][4][5][6][7][8][9][10]. One

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• organocatalysis using PhI (10 mol %)–mCPBA at ambient conditions as well as under neat mixing [115]. The N1,N1-dibenzylbenzene-1,2-diamine (Figure 27) which is an integrated system by the combination of aniline and N,N-dibenzylaniline led to the successful formation of 1-benzyl-2-phenyl-benzo[d]imidazole 48 under

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• , pyridine, 1 h, 0 °C to rt, 86% over two steps; c) HBPin, Pd(PPh3)4, Et3N, 1,4-dioxane, 24 h, 80 °C, 91%; d) PdCl2(PPh3)2, K2CO3, MeCN, H2O, 80 °C, 2 h, 86–95%; e) AcCl, pyridine, CH2Cl2, 3 h, rt; f) LiHMDS, THF, 100 °C, 2–6 h, 87–89%; g) Boc2O, DMAP, THF, 10 h, rt, 83–89%; h) ethane-1,2-diamine, TBAF, THF

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• starting fumarate [67]. Differently substituted piperazin-2-ones can be efficiently prepared by reacting dialkyl dicyanofumarates E-1 with alkane or cycloalkane-1,2-diamines. For example, the reaction with trans-cyclohexane-1,2-diamine (72) performed in acetonitrile at room temperature for 30 min gave the

• as single stereoisomers (79% yield) [63]. The same reaction pathway was observed in reactions with aromatic 1,2-diamines. For example, starting with benzene-1,2-diamine, the corresponding 2-oxo-1,2,3,4-tetrahydroquinoxaline derivatives, analogous to 73, were obtained in high yields as Z-isomers

High-speed vibration-milling-promoted synthesis of symmetrical frameworks containing two or three pyrrole units

• Marco Leonardi,
• Mercedes Villacampa and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2017, 13, 1957–1962, doi:10.3762/bjoc.13.190

• ), piperazine (1i,j) or tetramethyldisiloxane (1k–o) fragments, was also feasible. Interestingly, the use of N1-(2-aminoethyl)ethane-1,2-diamine as the starting material was also possible, without interference from the secondary amino group in spite of its nucleophilicity, to give compound 1h. This kind of

New metathesis catalyst bearing chromanyl moieties at the N-heterocyclic carbene ligand

• Agnieszka Hryniewicka,
• Szymon Suchodolski,
• Agnieszka Wojtkielewicz,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 2795–2804, doi:10.3762/bjoc.11.300

• (2,2,5,7,8-pentamethylchroman-6-yl)ethane-1,2-diamine (13) To a solution of 2,2,5,7,8-pentamethylchromanyl-6-amine (12, 500 mg, 2.3 mmol) in ethanol (96%, 20 mL), 2,3-dihydroxy-1,4-dioxane (138 mg, 1.15 mmol) and two drops of formic acid were added in a manner similar to a that described in [40]. The

Recent advances in copper-catalyzed asymmetric coupling reactions

• Fengtao Zhou and
• Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

• chelating ligands and thus compete with the chiral ligand for binding with the copper salts. Therefore the authors used a mono-aryl halide-substituted malonamide in the presence of a chiral CuI/1,2-diamine catalyst system and obtained the desired products in good yields and moderate enantioselectivities [48

Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

• David Porter,
• Belinda M.-L. Poon and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 2549–2556, doi:10.3762/bjoc.11.275

• David Porter Belinda M.-L. Poon Peter J. Rutledge School of Chemistry F11, The University of Sydney, NSW 2006, Australia 10.3762/bjoc.11.275 Abstract Iron(II) complexes of the tetradentate amines tris(2-pyridylmethyl)amine (TPA) and N,N′-bis(2-pyridylmethyl)-N,N′-dimethylethane-1,2-diamine (BPMEN

• iron complexes of tris(2-pyridylmethyl)amine (TPA, 1) [48][49], N,N′-bis(2-pyridylmethyl)-N,N′-dimethylethane-1,2-diamine (BPMEN, 2) [48][50] and (+)-(2R,2′R)-1,1′-bis(2-pyridylmethyl)-2,2′-bipyrrolidine ((R,R′)-PDP, 3) [51] (Figure 1) catalyse the allylic amination of cyclohexene. Mechanistic

• -pyridylmethyl)-N,N′-dimethylethane-1,2-diamine (BPMEN, 2) [50] were synthesised in good yields following literature procedures (Supporting Information File 1). (+)-(2R,2′R)-1,1′-Bis(2-pyridylmethyl)-2,2′-bipyrrolidine ((R,R′)-PDP, 3) was synthesised from commercially available (R,R′)-2,2′-bipyrrolidine L

A facile synthetic route to benzimidazolium salts bearing bulky aromatic N-substituents

• Gabriele Grieco,
• Olivier Blacque and
• Heinz Berke

Beilstein J. Org. Chem. 2015, 11, 1656–1666, doi:10.3762/bjoc.11.182

• of the benzimidazolium salts. Results and Discussion The starting point for the syntheses of the benzannulated NHCs 1-Cl, 2-Cl and 3-Cl was the development of a straightforward palladium-catalyzed preparation of the known N1,N2-diphenylbenzene-1,2-diamine compounds 5, 6 and 7 in dependence on an

• with the preparation of the N1,N2-di(pyridine-2-yl)benzen-1,2-diamine (8). The Buchwald–Hartwig amination was applied in the syntheses of 5 and 6 where 1,2-dichlorobenzene was coupled with aniline and 2,4,6-trimethylaniline, respectively (Scheme 1). Attempting the synthesis of the N1,N2-bis(2,6

• -diisopropylphenyl)benzene-1,2-diamine (7) and using 1,2-dichlorobenzene as the starting compound, the mono-substituted product was obtained. To avoid this complication 1,2-dibromobenzene had to be applied to eventually approach the preparation of 7. For 8 a reported synthetic procedure was used [48][49] consisting

The enantioselective synthesis of (S)-(+)-mianserin and (S)-(+)-epinastine

• Piotr Roszkowski,
• Jan. K. Maurin and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2015, 11, 1509–1513, doi:10.3762/bjoc.11.164

• highest enantiomeric excess 95%, but with only 26% chemical yield (Table 1, entry 6). Subsequently other catalysts were tested in order to improve the efficiency of the reduction. The catalyst 12, which is based on N-tosyl-(1S,2S)-1,2-diphenylethane-1,2-diamine (TsDPEN), gave amine 7 with 72–73% ee

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• ][14]. These methodologies will be mentioned where appropriate but not discussed in detail. Olefination Monocyclic phosphonamide reagents of type 1 bearing a N,N’-dialkylethane-1,2-diamine backbone were first reported as olefination reagents by Corey and Cane [15] and later by Savignac [16][17], and

• N,N’-dialkylethane-1,2-diamine phosphonamide 24 (Scheme 1 and Scheme 2). The reaction of anions 29 with ketones leads to the corresponding β-hydroxy phosphonamide intermediates 30, which undergo elimination of the intermediate oxaphosphetanes to give chiral olefins 31 with moderate to high

A complete series of 6-deoxy-monosubstituted tetraalkylammonium derivatives of α-, β-, and γ-cyclodextrin with 1, 2, and 3 permanent positive charges

• Martin Popr,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2014, 10, 1390–1396, doi:10.3762/bjoc.10.142

• mono-Ts-CD with neat N,N,N’-trimethylethane-1,2-diamine or N,N,N’-trimethylpropane-1,3-diamine and subsequent methylation by CH3I in good yields. Finally, analogues bearing a moiety with three tetraalkylammonium sites were synthesized by reacting mono-Ts-CD with bis(3-aminopropyl)amine and subsequent

• ], which neither provides the full NMR assignment of the intermediates and the product nor the yields of the reactions. In the first step, reagent N,N,N‘-trimethylethane-1,2-diamine (7) was easily prepared in one step by the published synthetic protocol [29], from inexpensive N-(2-chloroethyl)dimethylamine

New hydrogen-bonding organocatalysts: Chiral cyclophosphazanes and phosphorus amides as catalysts for asymmetric Michael additions

• Helge Klare,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2014, 10, 224–236, doi:10.3762/bjoc.10.18

• catalysts based on rigid cis-PV-cyclodiphosphazane amides of N1,N1-dimethylcyclohexane-1,2-diamine have been developed. Employed in the asymmetric Michael addition of 2-hydroxynaphthoquinone to β-nitrostyrene, the open-chain 9-epi-aminochinchona-based phosphorus amides show a high catalytic activity with

• -dimethylcyclohexane-1,2-diamine moieties inhibits a specific binding of the catalyst to the substrate. Exchanging one of the N1,N1-dimethylaminocyclohexylamino groups for an aniline moiety, as in catalyst 16, supports this. This sterically less demanding catalyst produced yields and selectivities (95% yield, 67% ee

• literature hitherto [47]. Preparation of cis-2,4-bis(((R,R)-2-(dimethylamino)cyclohexyl)amino)-1,3-diphenylcyclodiphosphazane-2,4-disulfide (14a): To a stirred solution of (R,R)-N1,N1-dimethylcyclohexane-1,2-diamine (400 mg, 2.81 mmol) in DCM (4 mL) was added a solution of 2,4-dichloro-1,3