Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones

• Carola Tortora,
• Christian A. Fischer,
• Sascha Kohlbauer,
• Alexandru Zamfir,
• Gerd M. Ballmann,
• Jürgen Pahl,
• Sjoerd Harder and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59

• isomer, with a more acute Ca–N–C angle of 92°, has greater resemblance to a (here absent) side-on form (found to dominate computationally for Ca(CN)2 in the gas phase) [54]. Fortunately, that isomer in which the isonitrile carbon is closer to the imine carbon (i.e., the hydrocyanation reaction center

• of 9 (with a collinear arrangement of Ca–C–N) was found to be a sizable 3.3 kcal·mol−1 higher in energy than the preferred isonitrile, conforming to earlier anticipations based on computations of alkaline earth metal dicyanides [54]. Similarly, it also has been recently observed that boron-catalyzed

New tandem Ugi/intramolecular Diels–Alder reaction based on vinylfuran and 1,3-butadienylfuran derivatives

• Yuriy I. Horak,
• Roman Z. Lytvyn,
• Andrii R. Vakhula,
• Yuriy V. Homza,
• Nazariy T. Pokhodylo and
• Mykola D. Obushak

Beilstein J. Org. Chem. 2025, 21, 444–450, doi:10.3762/bjoc.21.31

• insufficiently studied furo[2,3-f]isoindole derivatives. Ugi adducts formed from (E)-3-(furan-2-yl)acrylaldehyde, maleic acid monoanilide, isonitrile, and an amine spontaneously underwent the IMDAV reaction with a high level of stereoselectivity, leading to single pairs of enantiomers of 4,4a,5,6,7,7a-hexahydro

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• . From the mechanistic point of view, it is expected that the reaction proceeds via formation of an imine XXXIV between isoxazole carbaldehyde, activated by the copper salt, and 2-aminoazine, which in turn undergoes a non-concerted [4 + 1] cycloaddition involving isonitrile to give the imidazole ring of

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• (IEDDA), and recently, azomethine imine (AMIs)–isonitrile ligation [37][55][56][57][58][59][60]. The kinetics, chemoselectivity, stability, and steric demand of the bioorthogonal tag attached on the probe are decisive factors during the selection procedure [61][62]. The most commonly used strategy is

Deuterated reagents in multicomponent reactions to afford deuterium-labeled products

• Kevin Schofield,
• Shayna Maddern,
• Yueteng Zhang,
• Grace E. Mastin,
• Rachel Knight,
• Wei Wang,
• James Galligan and
• Christopher Hulme

Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195

• is comprised of reaction of an isonitrile, amine, and aldehyde/ketone, in the presence of phenylphosphinic acid (PPA), to give α-amino amides [35]. Examples of deuterated Ugi-3CR products are represented in Scheme 4. Like the Ugi 4-CR reaction, there was no deuterium scrambling in the Ugi 3-CR. Using

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• pyrazole starting materials from isonitriles 158, dialkyl acetylenedicarboxylate 147, and hydrazine carboxamide 159. The addition of the isonitrile to the Michael system yields a nitrilium-vinyl anion zwitterion 161, that is protonated by the hydrazine carboxamide, which undergoes addition to furnish the

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• showed biological activity according to the ChEMBL database. Keywords: fused rings; heterocycles; imidazoles; isonitrile; multicomponent reactions; Introduction Multicomponent reactions are widely recognized as a powerful source of biologically active compounds, in particular, for drug discovery

• purposes [1][2][3][4][5][6]. Isonitrile-based multicomponent reactions, such as the Groebke–Blackburn–Bienaymé (GBB) reaction, is an important tool in chemical synthesis providing easy access to a huge compound diversity and complexity [7][8][9][10][11][12][13][14][15][16][17]. Essentially, the GBB

• reaction is a three-component condensation of an α-amino heterocycle (e.g., 2-aminopyridine) 1, an aldehyde 2, and an isonitrile 3 providing the corresponding fused imidazoles (e.g., imidazo[1,2-a]pyridines) of general formula 4 (Scheme 1) [18][19][20][21]. Imidazo[1,2-a]pyridines and related heterocycles

Carbonylative synthesis and functionalization of indoles

• Alex De Salvo,
• Raffaella Mancuso and
• Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

• derivatives were isolated with good yields (Scheme 1). Instead, in the Senadi et al. approach, 1-(3-amino)-1H-indol-2-yl)-1-ketones were obtained through a Pd(0)-catalyzed cascade process consisting of isonitrile insertion as carbon monoxide surrogate and a C–H cross-coupling [13]. The reaction took place in

• the presence of K2CO3 (3 equiv) as base, an isonitrile (1.2 equiv), and Pd(OAc)2 (10 mol %) which in situ undergoes a reduction to Pd(0) (Scheme 2). Another example was published by Wu's group, who carried out the synthesis of 1-(1H-indol-1-yl)-2-arylethan-1-one derivatives by promoting the formation

• /carbonylation/Suzuki coupling reaction for the synthesis of 2-aroylindoles and 2-heteroaroylindoles. Pd(0)-catalyzed single isonitrile insertion: synthesis of 1-(3-amino)-1H-indol-2-yl)-1-ketones. Pd(0)-catalyzed gas-free carbonylation of 2-alkynylanilines to 1-(1H-indol-1-yl)-2-arylethan-1-ones. Pd(II

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• ), as shown in Scheme 1. In 2013, Shenvi and co-workers reported an operationally simple and high-yielding method for converting tertiary alcohols (including 3) to the corresponding primary amines via the intermediacy of an isonitrile [9]. This four-step procedure was conveniently carried out on a

A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• are high for EDGs (2d,e), while from good to high for the EWGs (2b,c). To confirm what has been previously stated, isonitrile 2a was recovered in lower yields than compound 2e (Scheme 3). At the end of the reaction, adding 0.5 equivalents of water for a 15 minute grinding step was necessary to

New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence

• Long Zhao,
• Mao-Lin Yang,
• Min Liu and
• Ming-Wu Ding

Beilstein J. Org. Chem. 2022, 18, 286–292, doi:10.3762/bjoc.18.32

• from aldehydes, a carboxylic acid, and a isonitrile as the three components [23]. The sequences of Passerini reactions, followed by post-condensation reactions, constitute useful synthetic methods in the preparation of structurally diverse heterocyclic compounds [24][25][26][27][28][29]. The aza-Wittig

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• 402160, China 10.3762/bjoc.17.193 Abstract Chemoselective sulfonylation and isonitrilation reactions for the divergent synthesis of valuable diarylmethyl sulfones and isonitrile diarylmethanes starting from easy-to-synthesize para-quinone methides (p-QMs) and commercially abundant p

• -toluenesulfonylmethyl isocyanide (TosMIC) by using respectively zinc iodide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalysts were developed. The distinguishing feature of this method is that TosMIC plays a dual role from the same substrates in the reaction: as a sulfonyl source or as an isonitrile source. The

• ; isonitrile diarylmethane; synthetic utility; Introduction Sulfones are ubiquitous units commonly found in marketed drugs and natural products. Because of their unique electronic and structural properties, they are often used in medicinal chemistry programs to search for anti-inflammatory, anti-HIV

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• ]phenanthridine 8.6 by the trifluoromethylation of methylenecyclopropane 8.2. The reaction started with the generation of the trifluoromethyl radical via the IrIII photocatalyzed reduction of Togni’s reagent 8.1. The fluorinated radical added onto the isonitrile group present in 8.2 to give radical 8.3·, which in

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• successfully undergo this cyclization (products 115f–h). C-centered radicals generated in a radical 5-exo-trig cyclization of β,γ-unsaturated oximes 116 upon oxidation by the TBAI/TBHP system were trapped by an isonitrile group of 2-arylphenyl isonitriles 117 to synthesize substituted phenanthridines 118

• (Scheme 38) [128]. Both aliphatic (example 118c) and aromatic (examples 118a,b,d–h) β,γ-unsaturated oximes enter this cascade cyclization. Relatively low yields were obtained with electron-withdrawing substituents in isonitrile 117 (examples 118g,h). Another example of a cascade oxidative cyclization

• involving an isonitrile group is the reaction of β,γ-unsaturated oximes 119 with vinyl isocyanides 120 to form substituted isoquinolines 121 (Scheme 39) [129]. Both α,α-disubstituted aromatic oximes (products 121a,b,e–h) and unsubstituted (R2 = R3 = H, products 121c,d) undergo the reaction successfully. The

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• /desulfonylation of the arylsulfonyl chlorides 14.1 (Scheme 14) [85][86]. The ensuing aryl radical is trapped by an aryl isonitrile 14.2, affording the bisarylation product 14.3. The direct organophotocatalytic activation of the C–H bond of an arene represents an atom-economical and attractive strategy for the

Microwave-assisted efficient and facile synthesis of tetramic acid derivatives via a one-pot post-Ugi cascade reaction

• Yong Li,
• Zheng Huang,
• Jia Xu,
• Yong Ding,
• Dian-Yong Tang,
• Jie Lei,
• Hong-yu Li,
• Zhong-Zhu Chen and
• Zhi-Gang Xu

Beilstein J. Org. Chem. 2020, 16, 663–669, doi:10.3762/bjoc.16.63

• ][39]. Spatz’ team reported a novel two-step synthetic procedure for the preparation of substituted tetramic acid derivatives via an Ugi/Dieckmann reaction [40]. A leaving amide that was derived from the isonitrile, provided the tetramic acid core under strong inorganic basic conditions. In this method

• , a convertible isonitrile promoted the cyclization, but restricted the scope of structural diversity. For this reason, it is desirable to replace the amide with a better leaving group, an ester group, which will undergo the Dieckmann reaction more effectively to form a five-membered ring. It is worth

Multicomponent reactions III

• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1974–1975, doi:10.3762/bjoc.15.192

• principle, recognized by Ugi's groundbreaking developments in isonitrile-based chemistry directly leads to one-pot methodologies as a reactivity-based concept [4]. Reactive functionalities that are repetitively being generated and transformed represent the basis of the underlying general principle

• Düsseldorf, Germany [7]. All contributions in this issue report or summarize recent developments of this highly dynamic field in a snap shot fashion. The agenda broadly spans over modern synthetic chemistry, from isonitrile and condensation-based MCRs over metal-catalyzed and mediated sequences to algorithms

Molecular basis for the plasticity of aromatic prenyltransferases in hapalindole biosynthesis

• Takayoshi Awakawa and
• Ikuro Abe

Beilstein J. Org. Chem. 2019, 15, 1545–1551, doi:10.3762/bjoc.15.157

• of cis-indolylvinyl isonitrile, but also on the C-2, which is supressed in the presence of Mg2+ ions. AmbP3 transfers the dimethylallyl group on C-2 of hapalindole U in the reverse manner, but on C-2 of its C-10 stereoisomer in the normal manner. This review highlights the molecular bases of the

• Hapalindole/ambiguine alkaloids, isolated from cyanobacteria, are composed of the total C15 prenyl moieties derived from dimethylallyl diphosphate (DMAPP) and geranyl diphosphate (GPP), and cis-indolylvinyl isonitrile 1 (Figure 2A) [15]. This natural product family includes structurally diverse compounds with

• beneficial bioactivities, exemplified by 12-epi-hapalindole E isonitrile, which exhibits antibacterial, antifungal, and antimycobacterial activities [16], and ambiguine I, which induces apoptosis and cell-cycle arrest through the inhibition of an NF-κB-related regulation pathway [17]. To investigate their

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• to be conducted at reflux to obtain a good yield of Ugi-derived steroids, albeit the procedure generated a pair of diastereomers (epimeric at C-5) in almost equal amount. The stereoselectivity of the intramolecular MCR increased when a bulky isonitrile was used, e.g., diethyl phosphonate isocyanide

Synthesis of (macro)heterocycles by consecutive/repetitive isocyanide-based multicomponent reactions

• Angélica de Fátima S. Barreto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2019, 15, 906–930, doi:10.3762/bjoc.15.88

• macroheterocycles in a reduced number of steps. Keywords: consecutive/repetitive multicomponent reactions; isocyanide; isocyanide-based multicomponent reactions; (macro)heterocycles; Passerini reaction; Ugi reaction; Introduction Isocyanide (isonitrile) chemistry was first described by Lieke in 1859 [1] and forms

Development of a method for the synthesis of 2,4,5-trisubstituted oxazoles composed of carboxylic acid, amino acid, and boronic acid

• Kohei Yamada,
• Naoto Kamimura and
• Munetaka Kunishima

Beilstein J. Org. Chem. 2017, 13, 1478–1485, doi:10.3762/bjoc.13.146

• prehalogenation [16]. iii) The multicomponent method: only two strategies have been reported to the best of our knowledge. One is a combination of the Ugi reaction, which uses 2,4-dimethoxybenzylamine, arylglyoxal, carboxylic acid, and isonitrile as components, and a subsequent Robinson–Gabriel reaction [17]. The

Regiochemistry of cyclocondensation reactions in the synthesis of polyazaheterocycles

• Patrick T. Campos,
• Leticia V. Rodrigues,
• Andrei L. Belladona,
• Caroline R. Bender,
• Juliana S. Bitencurt,
• Fernanda A. Rosa,
• Davi F. Back,
• Helio G. Bonacorso,
• Nilo Zanatta,
• Clarissa P. Frizzo and
• Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 257–266, doi:10.3762/bjoc.13.29

• multicomponent reaction between an α-ketoacid, a diamine such as 8d, an aldehyde, and an isonitrile Nixey et al. [32] observed an amide intermediate prior to the formation of the heterocyclic quinoxalinone. An intermediate amide was also observed by Sherman et al. [33] in the reaction between an α-ketoacid

Microwave-assisted synthesis of (aminomethylene)bisphosphine oxides and (aminomethylene)bisphosphonates by a three-component condensation

• Erika Bálint,
• Ádám Tajti,
• Anna Dzielak,
• Gerhard Hägele and
• György Keglevich

Beilstein J. Org. Chem. 2016, 12, 1493–1502, doi:10.3762/bjoc.12.146

• diphenylphosphine oxide to an isonitrile (Scheme 4b) [36][42]. In this paper, we wish to report the results of our investigations on the synthetic protocol utilizing the three-component condensations of primary or secondary amines, orthoformates and >P(O)H species, such as dialkyl phosphites or diphenylphosphine

On the mechanism of imine elimination from Fischer tungsten carbene complexes

• Philipp Veit,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

• ) [50][51][52] and during Si–O cleavage in the isonitrile complex W(CO)5(1,2-CN-C6H4-OSiMe3) (f) [53]. Synthesis of W(CO)5(E-2) from W(CO)5(1Et) [20][21] and aminoferrocene [40][41] with concomitant formation of E-1,2-diferrocenylimine E-3 [43] as side-product and atom numbering of W(CO)5(E-2) for NMR

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• urea dipeptide 27 [96][97]. Starting from the uridine derivative 28 used in the synthesis of (+)-caprazol, Ichikawa and Matsuda built up muraymycin D2 and its epimer (Scheme 4). They used an Ugi four-component reaction with an isonitrile derivative 29 obtained from the uridine-derived core structure 28