1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• transformations of aryl substrates have also been reported for thiovinyl ethers, and also for dihydrodithiins (Scheme 5), although there are obvious limitations to this point of view. Classical electrophilic aromatic substitution procedures such as the Vilsmeier–Haack reaction or a simple nitration have been

Direct synthesis of anomeric tetrazolyl iminosugars from sugar-derived lactams

• Michał M. Więcław and
• Bartłomiej Furman

Beilstein J. Org. Chem. 2021, 17, 115–123, doi:10.3762/bjoc.17.12

• . Although the Vilsmeier–Haack reaction [1] or amide reduction with LiAlH4 are textbook examples that easily come to mind, there are not many other methods available. Simple alkyl and aryl amides, unlike other carbonyl compounds, typically do not undergo direct addition by a nucleophile, including active

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

• Carlos H. Escalante,
• Eder I. Martínez-Mora,
• Carlos Espinoza-Hicks,
• Alejandro A. Camacho-Dávila,
• Fernando R. Ramos-Morales,
• Francisco Delgado and
• Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

• ). Derivative 21c was also prepared by the oxidation of 9h with manganese oxide at higher temperature, but the yield was lower (Table 4, entry 5). As part of our interest in further functionalizing octahydropyrrolo[3,4-e]indole-1,3-diones 9, formylation was herein investigated under usual Vilsmeier–Haack

• reaction conditions (Table 5). Fortunately, the series of 7-formyl derivatives 22a–e was attained in good yields. This synthetic approach allows for the preparation of widely polysubstituted octahydropyrrolo[3,4-e]indole-1,3-dione derivatives. However, the conversion into their aromatic skeleton either by

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• reactions were carried out. The starting substrates were easily obtained by a Vilsmeier–Haack reaction of bicyclo[3.2.1]octadiene thiophene derivatives with dimethylformamide. From the obtained carbaldehydes, novel methyl, methoxy, and cyano-substituted styryl thienobenzobicyclo[3.2.1]octadiene derivatives

• [3.2.1]octadiene compound with an extended conjugation. Keywords: bicyclo[3.2.1]octadiene; photocyclization; thiophene; Vilsmeier–Haack reaction; Wittig reaction; Introduction The bicyclo[3.2.1]octane skeleton has become the subject of intensive research in recent years [1][2][3]. Its presence in

• ' and 2', with different position of the sulfur in thiophene moiety, were selected. The compounds 1' and 2' were prepared according to the previously reported one-step photochemical methodology [15], and subjected to the Vilsmeier–Haack reaction (Scheme 2, Scheme 3), respectively. After chromatographic

Synthesis and properties of tetrathiafulvalenes bearing 6-aryl-1,4-dithiafulvenes

• Aya Yoshimura,
• Hitoshi Kimura,
• Kohei Kagawa,
• Mayuka Yoshioka,
• Toshiki Itou,
• Dhananjayan Vasu,
• Takashi Shirahata,
• Hideki Yorimitsu and
• Yohji Misaki

Beilstein J. Org. Chem. 2020, 16, 974–981, doi:10.3762/bjoc.16.86

• ; one was the palladium-catalyzed C–H arylation of TTF with bromide 12 (Scheme 2a) and the other was the Vilsmeier–Haack reaction of 1a, followed by triethyl phosphite-mediated cross coupling with 11 (Scheme 2b). Theoretical calculations The DFT calculations of compounds 1a, 3a, and 4 have been carried

Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179

• a decrease of their reaction times from >10 hours to 1–2 hours. Also, in some cases sonication greatly improved the yield, for example in a Vilsmeier–Haack reaction [21]; in addition selectivity can also be improved as demonstrated in a Pinacol coupling whereby a meso-isomer was the dominant product

Reactions of N,3-diarylpropiolamides with arenes under superelectrophilic activation: synthesis of 4,4-diaryl-3,4-dihydroquinolin-2(1H)-ones and their derivatives

• Larisa Yu. Gurskaya,
• Diana S. Belyanskaya,
• Dmitry S. Ryabukhin,
• Denis I. Nilov,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 950–956, doi:10.3762/bjoc.12.93

• -acetylation reactions were carried out. Compounds 2a,d,e and h were N-formylated in the system POCl3–DMF–CHCl3 under the Vilsmeier–Haack reaction conditions with formation of compounds 5a–d (Scheme 2). Apart from that, dihydroquinolinones 2a,e–h were acetylated into derivatives 6a–e (Scheme 2). Then reactions

Total synthesis of panicein A₂

• Lili Yeung,
• Lisa I. Pilkington,
• Melissa M. Cadelis,
• Brent R. Copp and
• David Barker

Beilstein J. Org. Chem. 2015, 11, 1991–1996, doi:10.3762/bjoc.11.215

• of panicein A2 Firstly, aldehyde 10 was required; it was prepared through methylation followed by Vilsmeier–Haack reaction of 2,3,5-trimethylphenol (11), giving 10 in 51% yield over two steps (Scheme 1) [7]. Aldehyde 10 then underwent an aldol reaction according to the procedures of Samokhvalov et al

Design and synthesis of hybrid cyclophanes containing thiophene and indole units via Grignard reaction, Fischer indolization and ring-closing metathesis as key steps

• Sambasivarao Kotha,
• Ajay Kumar Chinnam and
• Mukesh E. Shirbhate

Beilstein J. Org. Chem. 2015, 11, 1514–1519, doi:10.3762/bjoc.11.165

• Vilsmeier–Haack reaction starting with the thiophene [33]. Later, diol 6 was oxidized with MnO2 [34] to deliver diketone 3. Our attempts to realize the RCM product 2 with dione 3 via a reaction with Grubbs’ catalyst failed to give the expected cyclized product. In most instances, we observed the degradation

Studies on polynuclear furoquinones. Part 1: Synthesis of tri- and tetra- cyclic furoquinones simulating BCD/ABCD ring system of furoquinone diterpenoids

• Faruk H. Shaik and
• Gandhi K. Kar

Beilstein J. Org. Chem. 2009, 5, No. 47, doi:10.3762/bjoc.5.47

• -naphthaldehyde (a substrate easily available by Vilsmeier–Haack reaction on 2-tetralone) and furan-2-boronic acid (a commercially available material) (Figure 3). When 2-bromo-3,4-dihydro-1-naphthaldehyde (easily obtained in 68% yield by the reaction of 2-tetralone and PBr3/DMF in CHCl3 at room temperature) was

• polynuclear furoquinone derivatives bearing electron donating/electron withdrawing functionality within its framework as bromoaldehyde derivatives bearing such groups can easily be obtained from corresponding ketones by Vilsmeier–Haack reaction. Very recently we have reported a general method for the

• -tetralone by Vilsmeier-Haack reaction. Solvents were dried following standard literature procedure. Fremy’s salt (potassium nitrosodisulfonate) was prepared in the laboratory as per literature procedure [36]. 1H NMR spectra were recorded on Bruker 500 MHz (at Chemgen Pharma, Kolkata) and Bruker 400 MHz (at

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• presence of acetic anhydride to give the cis acetamido-acetate 183. The methylene side chain containing the methyl-carbamate was introduced via a Vilsmeier–Haack reaction and the aromatic ring was oxidized with the same method discussed in section 6.2 (vide supra). The synthesis was completed by selective