Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts

• Nils Clamor,
• Mattis Damrath,
• Thomas J. Kuczmera,
• Daniel Duvinage and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2

• fluorophors, previously shown to exhibit strong organic phosphorescence when mixed with specific additives [1][2][3][4][5]. Carbazole units are also found in drugs and natural products. They are also used in electrochemistry and as reagents in transamidation reactions [6][7][8][9][10][11][12]. The traditional

Synthesis of functionalized imidazo[4,5-e]thiazolo[3,2-b]triazines by condensation of imidazo[4,5-e]triazinethiones with DMAD or DEAD and rearrangement to imidazo[4,5-e]thiazolo[2,3-c]triazines

• Alexei N. Izmest’ev,
• Dmitry B. Vinogradov,
• Natalya G. Kolotyrkina,
• Angelina N. Kravchenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2021, 17, 1141–1148, doi:10.3762/bjoc.17.87

• is, probably, a result of a transamidation reaction upon the treatment with a base, for example, alkoxide anion. The nucleophilic attack of the alkoxide anion leads to the cleavage of the C(7)–N(8) bond to form intermediates B and C followed by the recyclization of the thiazolidine ring involving the

1,5-Phosphonium betaines from N-triflylpropiolamides, triphenylphosphane, and active methylene compounds

• Vito A. Fiore,
• Chiara Freisler and
• Gerhard Maas

Beilstein J. Org. Chem. 2019, 15, 2603–2611, doi:10.3762/bjoc.15.253

• (Scheme 2). They turned out to be excellent substrates for transamidation reactions (reaction 1) [18], whereas tertiary phosphanes Ph2P–X (X = SiMe3, Cl) underwent Michael addition leading to silylphosphanylation (reaction 2) or hydrophosphorylation (reaction 3) of the C–C-triple bond, respectively [19

• in transamidation reactions with nucleophilic amines [18][22]. Therefore, it was interesting to know the performance of propiolic acid chlorides in the same betaine syntheses. We found that acid chlorides 4 indeed underwent the three-component reaction with N,N’-dimethylbarbituric acid and furnished

Synthesis of indolo[1,2-c]quinazolines from 2-alkynylaniline derivatives through Pd-catalyzed indole formation/cyclization with N,N-dimethylformamide dimethyl acetal

• Antonio Arcadi,
• Sandro Cacchi,
• Giancarlo Fabrizi,
• Francesca Ghirga,
• Antonella Goggiamani,
• Antonia Iazzetti and
• Fabio Marinelli

Beilstein J. Org. Chem. 2018, 14, 2411–2417, doi:10.3762/bjoc.14.218

• , affording 2-(1H-indolo-2-yl)benzenamine derivatives 9 instead of products 8. We were pleased to observe the formation of 9a in good yields when 5 was reacted with 4-methoxyphenylboronic acid. A minor amount of product 11a (likely deriving from a transamidation reaction [25] of initially formed intermediate

Methyl isocyanide as a convertible functional group for the synthesis of spirocyclic oxindole γ-lactams via post-Ugi-4CR/transamidation/cyclization in a one-pot, three-step sequence

• Amarendar Reddy Maddirala and
• Peter R. Andreana

Beilstein J. Org. Chem. 2018, 14, 875–883, doi:10.3762/bjoc.14.74

• spiro[indoline-3,2'-pyrrolidine]-2,5'-diones, via a post-Ugi-domino transamidation/cyclization sequential process, has been achieved in three sequential steps utilizing a one-pot reaction protocol. The variation in carboxylic acid substrates allows for the generation of new chiral racemic quaternary

• carbon centers under basic conditions providing molecular diversity and a small library of spirocyclic oxindoles. Keywords: convertible isocyanides; lactams; molecular diversity; oxindoles; transamidation; Introduction The Ugi-multicomponent coupling reaction [1][2], followed by post-modification

• -substituted 2-indolinones through a three-step post-Ugi-4CR/Bechamp type-reduction followed by a transamidation sequence strategy [40], we came across interesting observations. We noted that when methyl isocyanide [41][42] was used for the Ugi-4CR and the subsequent post-intramolecular transamidation was

Recent advances in copper-catalyzed C–H bond amidation

• Jie-Ping Wan and
• Yanfeng Jing

Beilstein J. Org. Chem. 2015, 11, 2209–2222, doi:10.3762/bjoc.11.240

• chloride/anhydrides [6][7][8][9][10][11], nitrile hydrolysis [12][13][14][15][16], Goldberg C–N cross coupling reaction [17], aldehyde/ketone amidation [18][19][20][21][22][23], the transamidation [24][25][26][27][28][29], and oxime rearrangement [30][31][32][33], to name only a few. It is obvious that the

Molecular-oxygen-promoted Cu-catalyzed oxidative direct amidation of nonactivated carboxylic acids with azoles

• Wen Ding,
• Shaoyu Mai and
• Qiuling Song

Beilstein J. Org. Chem. 2015, 11, 2158–2165, doi:10.3762/bjoc.11.233

• scope. The mechanistic studies reveal that oxygen plays an essential role in the success of the amidation reactions with copper peroxycarboxylate as the key intermediate. Transamidation occurs smoothly between azole amide and a variety of amines. Keywords: amidation; azoles; Cu-catalyzed; molecular

• oxygen; transamidation; Introduction Amides are prevalent scaffolds in numerous compounds ranging from biologically active natural products to pharmaceuticals [1]. As a result, numerous methods have been developed for the formation of amides [2][3][4][5][6][7]. Despite such advances [8][9][10][11][12

• without formation of compound 20 (Scheme 3b). However, when a control experiment was conducted without benzimidazole (2) (Scheme 3c), compound 29 was not detected and the reaction resulted in a complex mixture of undesired compounds. In order to determine the possibility of transamidation between compound

Automated three-component synthesis of a library of γ-lactams

• Erik Fenster,
• David Hill,
• Oliver Reiser and
• Jeffrey Aubé

Beilstein J. Org. Chem. 2012, 8, 1804–1813, doi:10.3762/bjoc.8.206

• succinimide product 7{1,1,1} was also isolated as a single diastereomer, resulting from incomplete transamidation. Although the reductive amination occurred readily at room temperature, the lactamization appeared to occur more slowly than we had anticipated. In investigating individually the reductive