Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence to access phosphoric esters

• Jin Yang,
• Dang-Wei Qian and
• Shang-Dong Yang

Beilstein J. Org. Chem. 2022, 18, 1188–1194, doi:10.3762/bjoc.18.123

• desired 3aa being obtained at a temperature lower than 80 °C, but 4aa was produced in a high yield (Table 1, entries 7−9). When the reaction was performed at 120 °C, the yield of 3aa was slightly lower than that at 100 °C. With the high-yielding reaction conditions established (Table 1, entry 5), we

• formaldehyde or ketone groups could also be transformed into the desired diphosphination products 3bm and 3bn in moderate to good yield. The generality of the system was further showcased by tolerating quinoline and isoquinoline groups, and the desired products 3bp and 3bq were afforded in a high yield

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• proceeds smoothly at room temperature giving rise to cyclopropane 4 in excellent diastereoselectivity (de = 92%) and high yield. The optical purity of the starting compounds was confirmed by comparison of the optical rotation data with previously published values (see Supporting Information File 1

Synthesis of tryptophan-dehydrobutyrine diketopiperazine and biological activity of hangtaimycin and its co-metabolites

• Houchao Xu,
• Anne Wochele,
• Minghe Luo,
• Gregor Schnakenburg,
• Yuhui Sun,
• Heike Brötz-Oesterhelt and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 1159–1165, doi:10.3762/bjoc.18.120

• [17] gave (Z)-4 as a single diastereomer through anti elimination. Overall, TDD was obtained from ʟ-tryptophan in a high yield of 37% over eight linear steps. HPLC analysis on a chiral stationary phase showed that 4 obtained through this second route was enantiomerically enriched (80% ee by peak

• temperature. Also the addition of base (NEt3) did not promote the reaction. Therefore, the mode of action of TDD towards glutathione S-transferase needs further investigation. Conclusion We have established an efficient synthesis of TDD that makes this compound available from ʟ-tryptophan with a high yield of

Electrogenerated base-promoted cyclopropanation using alkyl 2-chloroacetates

• Kouichi Matsumoto,
• Yuta Hayashi,
• Kengo Hamasaki,
• Mizuki Matsuse,
• Hiyono Suzuki,
• Keiji Nishiwaki and
• Norihito Kawashita

Beilstein J. Org. Chem. 2022, 18, 1116–1122, doi:10.3762/bjoc.18.114

• was 44% in the case of 0.90 F/mol (Table 2, entry 2). However, using 1.1 F/mol resulted as well in a lower yield of 2 (<35%, Table 2, entry 3). Thus, 0.90 F/mol or 1.0 F/mol of electricity for the current reaction was found to be sufficient to obtain the product in high yield, and we choose 1.0 F/mol

Electrochemical formal homocoupling of sec-alcohols

• Kosuke Yamamoto,
• Kazuhisa Arita,
• Masashi Shiota,
• Masami Kuriyama and
• Osamu Onomura

Beilstein J. Org. Chem. 2022, 18, 1062–1069, doi:10.3762/bjoc.18.108

• 2a in a high yield, and we chose 125 μL of H2O as the optimal volume for the present transformation (Table 1, entries 11–13). The reaction under inert atmosphere did not improve the yield of 2a (Table 1, entry 14). With the optimized conditions in hand, the substrate scope of the present

Electrochemical hydrogenation of enones using a proton-exchange membrane reactor: selectivity and utility

• Koichi Mitsudo,
• Haruka Inoue,
• Yuta Niki,
• Eisuke Sato and
• Seiji Suga

Beilstein J. Org. Chem. 2022, 18, 1055–1061, doi:10.3762/bjoc.18.107

• . Linear enone 1f gave the desired ketone 2f in high yield (88%, 97% selectivity). Reduction with the PEM reactor also proceeded smoothly with enone 1g, which has a cyclohexene moiety, to give the corresponding ketone 2g in 87% yield (91% selectivity). As shown so far, several kinds of enones 1 could be

• subjected to electroreduction using the PEM reactor to afford ketones in high yield and selectivity. Electroreduction of enones to saturated alcohols We next examined the electrochemical reduction of several enones 1 to saturated alcohols 3 using an Ir/C catalyst for the cathode (Scheme 3). Full conversion

Automated grindstone chemistry: a simple and facile way for PEG-assisted stoichiometry-controlled halogenation of phenols and anilines using N-halosuccinimides

• Dharmendra Das,
• Akhil A. Bhosle,
• Amrita Chatterjee and
• Mainak Banerjee

Beilstein J. Org. Chem. 2022, 18, 999–1008, doi:10.3762/bjoc.18.100

• the usefulness of the current protocol for quick access to these halo derivatives. Encouraged by this, we attempted monochlorination with selected phenols and anilines. The first attempt with 2-naphthol afforded the desired chloro derivative 2ah in high yield within 2 min. However, unlike in the case

• used (Scheme 4). The formation of the corresponding monobromo products was not observed. Similarly, p-cresol (1a) was converted to the corresponding diiodo derivative 3i in high yield by using 2.1 equiv of NIS indicating the generality of this synthetic protocol. Next, the attempted dihalogenation of

Morita–Baylis–Hillman reaction of 3-formyl-9H-pyrido[3,4-b]indoles and fluorescence studies of the products

• Nisha Devi and
• Virender Singh

Beilstein J. Org. Chem. 2022, 18, 926–934, doi:10.3762/bjoc.18.92

• ester 4a–e in high yield (83–87%) and ester functionality reduction with LiAlH4 in dry THF yielded the alcohols 5a–e in excellent yield (90–98%). The required 3-formyl-9H-β-carbolines 6a–e were obtained in 73–88% yield by oxidizing the alcohol derivatives 5a–e with MnO2 in dry DCM. The present

Cathodic generation of reactive (phenylthio)difluoromethyl species and its reactions: mechanistic aspects and synthetic applications

• Sadanobu Iwase,
• Shinsuke Inagi and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2022, 18, 872–880, doi:10.3762/bjoc.18.88

• 1,1-diphenylethylene as a more electron-rich olefin compared to α-methylstyrene was carried out similarly. As expected, the adduct 6 was formed in a high yield of 90% as shown in Scheme 10. Isopropanol can serve as both a proton and a hydrogen radical source while cumene serves only as a hydrogen

• -methylstyrene consumed less than 2 F/mol of electricity to provide protonated and deuterated adducts 4/4D in almost same yields. Similar indirect electrolysis of compound 1 in iPrOH/MeCN in the presence of 1,1-diphenylethylene consumed much more than 2 F/mol of electricity to afford adduct 6 in high yield

Palladium-catalyzed solid-state borylation of aryl halides using mechanochemistry

• Koji Kubota,
• Emiru Baba,
• Tamae Seo,
• Tatsuo Ishiyama and
• Hajime Ito

Beilstein J. Org. Chem. 2022, 18, 855–862, doi:10.3762/bjoc.18.86

• smoothly and provided the desired product 3f in high yield (84%). Also, the reaction of (4-chlorophenyl)(phenyl)methanone (1r) afforded the corresponding product 3q in good yield. To demonstrate the practical utility of the developed protocol, the solid-state borylation reaction was investigated on a gram

• afforded the borylation product 3a in high yield, which was comparable to the yield obtained at the 0.3 mmol scale. We confirmed by thermography that the internal temperature after the reaction was approximately 100 °C. Conclusion In summary, we have developed the first protocol for the solid-state

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• reaction. After filtration through activated aluminum, (S)-α-phellandrene (30) is obtained in a high yield of 88% over three steps on a 30 g scale corresponding to a productivity of 0.887 mol/day [36]. The smell of leaves and freshly cut green grass can mainly be traced back to (Z)-hex-3-en-1-ol (32) (so

An isoxazole strategy for the synthesis of 4-oxo-1,4-dihydropyridine-3-carboxylates

• Timur O. Zanakhov,
• Ekaterina E. Galenko,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2022, 18, 738–745, doi:10.3762/bjoc.18.74

• )-one 14 in 89% yield. The reaction of pyridone 2e with PBr3 afforded methyl 4-bromo-6-(4-fluorophenyl)-2-phenylnicotinate (15) in 80% yield. The latter was employed in the Suzuki reaction in the high-yield synthesis of 2,4,6-triaryl-substituted nicotinate 16. The nitrogen of 2,3,4,6-tetrasubstituted

• rearrangement of methyl 2-(isoxazol-5-yl)-3-oxopropanoates 1. High yield transformations of compound 2 provide easy access to 2,4,6-triaryl-substituted and 1,2,5,6-tetrasubstituted nicotinates. Approaches to the synthesis of alkyl 4-oxo-1,4-dihydropyridine-3-carboxylates. Synthesis of 4-oxo-1,4-dihydropyridine

Rapid gas–liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide

• Kyoko Mandai,
• Tetsuya Yamamoto,
• Hiroki Mandai and
• Aiichiro Nagaki

Beilstein J. Org. Chem. 2022, 18, 660–668, doi:10.3762/bjoc.18.67

• with good operational stability, evaluated by a constant high yield of cyclohexene oxide, to obtain the desired product with high productivity. Keywords: air; continuous flow; cyclohexene oxide; flow epoxidation; rapid gas–liquid reaction; Introduction From the past to the present, organic synthesis

• achieved by using a flow technique (Scheme 1). Cyclohexene oxide was selectively produced with high yield in our flow oxidation system using air and within only 1.4 min. The fast epoxidation of cyclohexene without added catalyst in the solution was achieved since the solution of cyclohexene and aldehyde in

• . Conclusion In the present study, we developed the continuous flow system for the aerobic cyclohexene oxide production based on appropriate temperature and residence time control. Moreover, the production of cyclohexene oxide with high yield and selectivity was achieved under the conditions of a very short

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• (73%) and 109b (82%) in high yield (Figure 23b) [110], although the relevant distances in the pseudo-rotaxane 110a,b (prior to the second click reaction) are 14.3 and 21.1 Å. Actually, the yield with [FeCu2(104)2]4+ was far better than with a dicopper reference catalyst, where the separation of the

Unusual highly diastereoselective Rh(II)-catalyzed dimerization of 3-diazo-2-arylidenesuccinimides provides access to a new dibenzazulene scaffold

• Anastasia Vepreva,
• Alexander S. Bunev,
• Andrey Yu. Kudinov,
• Grigory Kantin,
• Mikhail Krasavin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55

• shown to strongly depend on the nature of the substituents in the diazo substrate. The new reaction provides access to dibenzoazulenodipyrrole and indenopyrrole derivatives in moderate to high yield. Dibenzoazulenodipyrroles bearing alkyl substituents at the nitrogen atom showed pronounced cytotoxocity

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• acceptors. The obtained vesicles could be utilized as a nanoreactor for photocatalyzed dehalogenation reactions in water. However, the above reported supramolecular nanosystem requires a long time to produce the dehalogenated product with high yield. Therefore, the development of a potential nanoreactor for

Synthesis of piperidine and pyrrolidine derivatives by electroreductive cyclization of imine with terminal dihaloalkanes in a flow microreactor

• Yuki Naito,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2022, 18, 350–359, doi:10.3762/bjoc.18.39

• the desired product 3a in a high yield. Table 3 shows the effect of the electrode distance on the yield of the reduction products 3a and 4. From these results, the optimal electrode distance was determined to be 40 µm (Table 3, entry 2). When the electrode distance was increased to 80 µm, the yield of

• environment for the reduction of imine 1 is considered to result in the high yield of 3a. To confirm that the reaction environment of the flow system was in the steady state, the electrolyzed solution was collected from the reactor outlet at regular intervals and the yield of 3a for each fraction was

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• compatible with the catalyst and afforded the products with high yield. The efficiency of the catalyst in water was found to be increased by introducing polyethylene glycol (PEG) chains. From the mechanistic explanation, the reaction proceeds via an oxidative addition and reductive elimination route. Fe3O4

Asymmetric organocatalytic Michael addition of cyclopentane-1,2-dione to alkylidene oxindole

• Estelle Silm,
• Ivar Järving and
• Tõnis Kanger

Beilstein J. Org. Chem. 2022, 18, 167–173, doi:10.3762/bjoc.18.18

• oxindole and the squaramide decreasing the effective concentration of the catalyst. Taking this into consideration, 2 equiv of substituted oxindole was used and the reaction proceeded smoothly in 2 h in high enantioselectivity (90%/94% ee), in high yield (74%) but in moderate diastereoselectivity (Table 1

Efficient and regioselective synthesis of dihydroxy-substituted 2-aminocyclooctane-1-carboxylic acid and its bicyclic derivatives

• İlknur Polat,
• Selçuk Eşsiz,
• Uğur Bozkaya and
• Emine Salamci

Beilstein J. Org. Chem. 2022, 18, 77–85, doi:10.3762/bjoc.18.7

• this transformation. The structure of 13 was elucidated with the help of the 2D NMR (COSY and HMQC) experiments. Finally, removal of the Boc group from 13 with HCl(g)–MeOH resulted in the formation of cyclic β-amino acid derivative 8 in high yield. Our suggested mechanism for the reaction of epoxide 7

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• also important in quantitative analytical determinations of drugs containing free primary and secondary amino groups, as they react quickly and in high yield with amines to form colored products in good yields. This review reports several examples of syntheses of functionalized 1,2-naphthoquinones

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• as solvent (Scheme 23). Both aromatic and aliphatic aldehydes performed well and gave the desired products in good yields. At the same time ketones were found less active in this strategy. The operational simplicity and high yield of products are the prominent characteristics of this reaction. In

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• achieved by solid-state synthesis. Our synthetic strategy could synthesize the target peptide in high yield with good purity Keywords: antimalarial; highly methylated polypeptides; hoshinoamides; total synthesis; Introduction Malaria is an insect-borne infectious disease caused by parasites of the genus

• synthesized in high efficiency. After systematic screening of the coupling reagents in liquid phase, the key intermediate tripeptide 7 was obtained in high yield. The solid-phase synthesis improves the entire efficiency of the synthetic route. This strategy could be applied to the stereoselective synthesis of

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• co-workers established a Heck/Kumada cross-coupling cascade to construct nitrogen and oxygen-containing cis-heterospirocycles 40 in high yield and diastereoselectivity with inexpensive Fe(acac)3 as the precatalyst (Scheme 8) [73]. Interestingly, this protocol was applicable to substrates bearing

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

• ]. Zhou and co-workers published an excellent paper in 2019 on the conversion of central to axial chirality in an enantioselective [3 + 2] annulation of 1-styrylnaphthols 32 with azonaphthalenes 33. Under defined conditions, the cycloaddition product 34 was prepared in high yield (99%) with exclusive

• -axial chirality conversion by oxidative aromatization. With excellent diastereoselectivities (all >20:1) and enantioselectivities (87–99% ee), the target products 35 containing different groups were obtained in high yield (up to 94%) (Scheme 12). In this transformation, electron-donating and withdrawing

• chiral arylquinazolinones 76 were obtained in high yield (up to 99%) with high enantioselectivity (83–97% ee, Scheme 25). Both the position and the electronic properties of the substituents on the aromatic ring had a minor influence on the reaction efficiency and enantioselectivity of this transformation