Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

• Andrey R. Galeev,
• Maksim V. Dmitriev,
• Alexander S. Novikov and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

• -aminopyridine, provided N-hetarylaniline (3af) in moderate yield. Furthermore, it is possible to synthesize sterically hindered anilines such as arylamine 3ah, which was prepared from 2,6-di(isopropyl)aniline in 53% yield. However, in the case of an electron-deficient amine (4-trifluoromethylaniline), the

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• -substituted indazole analogs in 44% and 40% yields, respectively, by treating compound 6 with methyl iodide and potassium carbonate in dimethylformamide (DMF) at room temperature for 17 h [40]. Other works have shown poor selectivity when 6 and other isomers similar to 6 were reacted with isopropyl iodide and

• potassium carbonate, isopropyl bromide and cesium carbonate, and bromocyclohexane with potassium carbonate, and only afforded yields not higher than 52% in various solvents [41][42][43]. Recently, Alam and Keeting [37] explored the regioselectivity in the alkylation of variously substituted indazoles

• Scheme 1 compound 6 was treated with isopropyl iodide (7) in DMF in the presence of sodium hydride to provide products 8 and 9 in 38% and 46% yields, respectively. The structures of both compounds were unambiguously assigned using X-ray crystallography and 1H and nuclear Overhauser effect (NOE) NMR

Solvent-dependent chemoselective synthesis of different isoquinolinones mediated by the hypervalent iodine(III) reagent PISA

• Ze-Nan Hu,
• Yan-Hui Wang,
• Jia-Bing Wu,
• Ze Chen,
• Dou Hong and
• Chi Zhang

Beilstein J. Org. Chem. 2024, 20, 1914–1921, doi:10.3762/bjoc.20.167

• , isopropyl, cyclopropyl, phenyl, or hydrogen, respectively, the intramolecular amination smoothly gave the corresponding 4-substituted isoquinolinone products 2b,c,d–f in 51–94% yield. Notably, when 1c was used as the substrate, the cycloisomerization product 2c' was observed in 31% yield besides 2c in 51

• of 3-methylisoquinolinone as follows: reacting 1.1 equivalents of PISA in HFIP (0.1 M of 1a) containing 2.5 equivalents of H2O at room temperature for 20 minutes (Scheme 3). The general applicability of PISA in wet HFIP solvent was studied. When R1 was ethyl, isopropyl, cyclopropyl, or hydrogen

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• alcohol, isopropyl alcohol, and toluene) increased the reactivity of MtCh509 relative to the aqueous system, representing the first solvent‑tolerant chitinase from Microbulbifer species and its potential applications in industrial processes [50]. rChi1602 exhibited maximal activity at 60 °C and over a

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• components, such as various acrylates, α,β-unsaturated acids, enones, enals, acrylamides, vinyl phosphonates, and vinyl sulfones. Various cesium salts of oxalates also performed well using this protocol. Isopropyl and tert-butyl groups present in an adjacent position of oxalates do not disturb the reaction

Oxidative hydrolysis of aliphatic bromoalkenes: scope study and reactivity insights

• Amol P. Jadhav and
• Claude Y. Legault

Beilstein J. Org. Chem. 2024, 20, 1286–1291, doi:10.3762/bjoc.20.111

• isobutyl groups at the distal side of bromoalkene was readily tolerated and yielded the products (2c,d) with consistent yields. Demonstrating additional generalizability, substrates bearing sterically demanding cyclohexyl or isopropyl groups as the near side chain of bromoalkene afforded the corresponding

Cofactor-independent C–C bond cleavage reactions catalyzed by the AlpJ family of oxygenases in atypical angucycline biosynthesis

• Jinmin Gao,
• Liyuan Li,
• Shijie Shen,
• Guomin Ai,
• Bin Wang,
• Fang Guo,
• Tongjian Yang,
• Hui Han,
• Zhengren Xu,
• Guohui Pan and
• Keqiang Fan

Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102

• . Both plasmids were confirmed by sequencing and transformed into E. coli BL21(DE3). Protein overproduction was induced with 0.1 mM isopropyl β-ᴅ-thiogalactopyranoside at 16 °C for 15 h. Cells were collected by centrifugation (8,000g, 15 min) at 4 °C. The pellets were resuspended in ice-cold 50 mM 3-(N

Kinetically stabilized 1,3-diarylisobenzofurans and the possibility of preparing large, persistent isoacenofurans with unusually small HOMO–LUMO gaps

• Qian Liu and
• Glen P. Miller

Beilstein J. Org. Chem. 2024, 20, 1099–1110, doi:10.3762/bjoc.20.97

• substituents, respectively, were also attempted but without success. In these cases, the sterically congesting ortho isopropyl and tert-butyl groups stymie the Friedel–Crafts acylation step leading to diketone (Scheme 1). Experimental and computational studies of 1,3-diarylisoacenofurans Purified

Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

• Kara A. Strickland,
• Brenda Martinez Rodriguez,
• Ashley A. Holland,
• Shelby Wagner,
• Michelle Luna-Alva,
• David E. Graham and
• Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

• products. Experimental General reagents and protocols Isopropyl β-ᴅ-1-thiogalactopyranoside (IPTG) and 5-aminolevulinic acid (5-ALA) were purchased from Gold Biotechnology. NNG was purchased from AAblocks. 2-NAE was purchased from Toronto Research Chemicals. General buffers and media components were

• were used to inoculate 100 µL of selective growth media (1/5 LB media, 20 µM isopropyl β-ᴅ-thiogalactopyranoside (IPTG), 300 µM 2-NAE or 3 mM NNG, and antibiotic) in a 96-well plate. After overnight incubation at 37 °C, the cells were pelleted by centrifugation and the nitrite quantified by Griess

Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• structures for the Henry reaction. The preparation of 5-isopropyl-5-methyl-2-(pyridin-2-yl)imidazolidin-4-one derivatives and their application in asymmetric Henry reaction [5]. Asymmetric Henry reactions of various aldehydes with nitromethane catalysed by copper(II) complexes of ligands Ia–c. Asymmetric

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• overnight. Then, 1 L LB medium supplemented with 25 µg/mL kanamycin was inoculated with 25 mL of the pre-culture and incubated at 37 °C, 180 rpm. When OD600nm reached 0.4, the temperature was lowered to 16 °C, and when OD600nm reached 0.8, protein expression was induced by the addition of 0.1 mM isopropyl β

Synthesis of spiropyridazine-benzosultams by the [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes

• Wenqing Hao,
• Long Wang,
• Jinlei Zhang,
• Dawei Teng and
• Guorui Cao

Beilstein J. Org. Chem. 2024, 20, 280–286, doi:10.3762/bjoc.20.29

• detected and a similar result was observed as for the R3 group (Scheme 2, 3ah,ai vs 3aj,ak,al). To further expand the substrate scope, we next tested other 3-substituted benzoisothiazole 1,1-dioxides 1a–c. As seen from Scheme 2, dienophiles with a bulky and branched isopropyl group (1b) could also be

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• OD600 reached 0.8. After the culture was cooled on ice for 30 min, isopropyl β-ᴅ-thiogalactopyranoside (IPTG) was added to the culture (for CmaA1 and CmaA3 expression, final concentration was 100 µM; for CmaA6 expression, IPTG was not added) and incubated with shaking (150 rpm) at 15 °C for 20 h. Cells

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• desired cycloadduct, although in a modest 30% yield [69]. The subsequent alkylation of N3 with methyl, ethyl, or isopropyl iodide afforded triazolium salts 5a–f in satisfactory to excellent yields. It should be pointed out that compounds 5c–f had never been described before (see the Supporting Information

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• groups representing (a) isopropyl and (b) sec-butyl, were successfully obtained in 84% and 61% yields, respectively. The incorporation of a biphenylene group into the azaacene structure did not result in any significant impact on the electrochemical properties. The electrochemical analysis revealed the

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• transport [37][38]. Therefore, to better understand the charge mobility of compounds 1 and 2, we obtained their ground state geometry using DFT within the B3LYP/def2-TZVP(-f) level of theory (Figure 8a). To reduce computational efforts, isopropyl moieties were used instead of the large aliphatic

• of the optimized isopropyl derivatives geometry are presented in Supporting Information File 1. Conclusion The electron and hole-transporting characteristics of two columnar liquid crystals were evaluated with electron-only and hole-only devices. Compound 1 is a perylene-based molecule presenting a

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• mg) was separated by PTLC (petroleum ether/isopropyl alcohol 10:1) to afford eight fractions (Fr.6.7.9.5.14.1–Fr.6.7.9.5.14.8). Fr.6.7.9.5.14.3 (25.4 mg) was further purified by semi-preparative HPLC on YMC-PACK-ODS-A (aqueous MeCN, 65%) to yield 1 (12.7 mg, tR = 28.1 min, flow rate: 3 mL/min). Fr

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• Sargent [18] synthesised pacharin (13) using a novel method through oxidation of a bisphosphonium diphenyl ether prepared in situ from dibromide 130 (Scheme 28). On treatment with base and exposure to oxygen, the diylide intermediate underwent oxidative coupling to give the isopropyl-protected dibenzo[b,f

Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

• Ekaterina A. Lystsova,
• Maksim V. Dmitriev,
• Andrey N. Maslivets and
• Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

• yields of the corresponding products 3 and the general course of the reaction. However, the structure of the alcohols 2a–c had an effect on the studied reaction. Reactions with isopropyl alcohol 2b required longer reaction times (UPLC–UV–MS monitoring). This phenomenon could be due to the steric factors

• brought in by a bulky isopropyl substituent in alcohol 2b. In addition, in all studied cases we observed that the reaction of APBTTs 1 with alcohols 2 always afforded labile side-products 5 (Scheme 9). Compounds 5 were formed when the nucleophile 2 attacked on the position C3a of the substrates 1. Such a

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• noted decreasing the steric bulk of the amide moiety of the substrate from isopropyl to ethyl to methyl decreased the enantioselectivity of the reaction. Carbon- and nitrogen-bridging bicyclic alkenes were also identified as competent substrates. In this respect, norbornadiene was found to give the

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• , in this work, we show that another major constituent of the male specific gland is (10R,1S,6R,7R,10R)-amorph-4-ene-10β-ol [(1R,4R,4aR,8aS)-4-isopropyl-1,6-dimethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-1-ol]. This compound was synthesized for the first time and has the opposite configuration to

• an equatorial isopropyl group and axial OH in compound 14. A more detailed description showing the relevant NOESY correlations is given in Supporting Information File 1. Compound 14 proved to be identical to amorph-4-en-10β-ol, which is a rare natural product, known from the wood oil of Cryptomeria

• define the first stereogenic center at the isopropyl group, which becomes C-4 in the final products. Both S- and R-16 were used to obtain the respective products in high ee and high yields (R-17 = 87%, 98% ee, S-17 = 87%, 99% ee) (Scheme 2) [20]. As in the racemic synthesis (Scheme 1), a HWE reaction

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• an isopropyl. The COSY correlation H-38 (δH 2.41, 2.38)/H-39 (δH 5.00) which for this spin system is largely extended by the gHSQC-TOCSY correlations C-38 (δC 40.4)/H-39 (δH 5.00), C-39 (δC 71.6)/H-38 (δH 2.41, 2.38), H-40 (δH 1.55), H-41 (δH 1.21), H-42 (δH 1.21), H-43 (δH 1.21), H-44 (δH 1.21), H

• 1.21), H-43 (δH 1.21), H-44 (δH 1.21), H-45 (δH 1.21), H-46 (δH 1.21), and C-48 (δC 39.7)/H-50 (δH 0.86) fully confirms the aliphatic side chain terminating by an isopropyl moiety. Some of the HMBC correlations used to support this substructure are, H-38 (δH 2.41, 2.38)/C-39 (δC 71.6), H-39 (δH 5.00)/C

• examine similar lipopeptide structures previously characterized in the literature that possessed both the fatty acid chain terminating as an isopropyl and adjacent to Glu residue connected by an amide bond. This detailed examination revealed that in the structure of these cyclic lipopeptides, the

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• distillation, to the first column also allows for the collection of unreacted phosphite, and byproducts, such as isopropyl bromide. Firstly, this prevents any release of vapours of toxic compounds and facilitates appropriate disposal procedures. Secondly, it is likely that the majority of what remains in the

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH₄I

• Shang-Feng Yang,
• Pei Li,
• Zi-Lin Fang,
• Sen Liang,
• Hong-Yu Tian,
• Bao-Guo Sun,
• Kun Xu and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2022, 18, 1249–1255, doi:10.3762/bjoc.18.130

• ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and cyclohexyl moieties were also compatible with the optimized conditions, providing the corresponding 2-aminothiazoles in 24% to 65% yields (3g–l). As shown in Scheme 2, when the R1 group changed from alkyl to aryl, the target products could also be

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• 16 °C and induced with 0.1 mM isopropyl β-ᴅ-1-thiogalactopyranoside (IPTG) for 16 h. Cells were harvested by centrifugation (10 min, 8,000 rpm, 4 °C). For protein purification, cell pellets were resuspended in lysis buffer (50 mM NaH2PO4, 400 mM NaCl, 1 mM TCEP, pH 7.5) and lysed by sonication. After