Enhancing structural diversity of terpenoids by multisubstrate terpene synthases

• Min Li and
• Hui Tao

Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86

• , that bind trinuclear magnesium clusters for diphosphate abstraction, whereas class II TSs have a DXDD motif that acts as the catalytic acid. Recently, several novel unconventional TSs that share low sequence and structural similarities with classical TSs have been discovered and comprehensively

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• was added, followed by thorough extraction. The combined organic layer was dried over magnesium sulfate, filtered, and dried under reduced pressure. The remaining residue was purified via column chromatography (gradient ethyl acetate/hexane) to afford 6-bromo-5-(2-fluorophenyl)[1,3]thiazolo[4,5-b

• pyrrolidinedithiocarbamate (328 mg, 2.00 mmol, 0.44 equiv). The reaction mixture was stirred for 1 h at room temperature, and the organic layer was washed with saturated sodium hydrogencarbonate solution, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The remaining residue was purified via

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• the corresponding =CF2 containing products [10]. In addition to complexes of aluminum and boron, several magnesium and lithium silyl reagents were prepared and proved to be good nucleophiles in reactions with (Z)-1,1,1,4,4,4-hexafluorobut-2-ene, as a result of which the corresponding

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• -halides [115]. Their optimized reaction conditions required a NiII precursor, 2,2’-bipyridine (bpy) as ligand, silver nitrate (AgNO3) as an additive and the combination of a magnesium (Mg) sacrificial anode and a RVC cathode (Scheme 35A). A crucial discovery in advancing this methodology was the in situ

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• increasing voltage (CELIV) or MIS-CELIV technique [59][60][61]. Electron- and hole-only MIS devices were fabricated with the structures of indium tin oxide (ITO)/magnesium fluoride (MgF2) (20 nm)/TPECNz (100 nm)/lithium fluoride (LiF) (1 nm)/aluminum (Al) (100 nm) and ITO/MgF2 (20 nm)/TPECNz (100 nm

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• sodium(I), zinc(II), magnesium(II), and barium(II) [106][107][108][109]. Association constants of the reported host–guest complexes showed similar values to those of diazacrown ethers [110][111]. Johnston and Gunter presented a crown ether-capped porphyrin receptor 10, which showed unexpected binding

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• the synthesis of trifluoromethyl aromatic acyloins. Maekawa’s group [24] developed a tandem reaction of the reductive coupling between arylaldehydes and ethyl trifluoroacetate in the presence of magnesium and chlorotrimethylsilane, followed by desilylation to produce the trifluoromethyl aromatic

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• , 80 mmol), the mixture was extracted with ethyl acetate (30 mL × 3), and the organic layer was washed with brine (30 mL × 1), dried over magnesium sulfate, and concentrated to afford nitrostyrene 2a (17.4 g, 71%, mp 56–58 °C) as a yellow solid. Nitrostyrene 2b (mp 112–114 °C) was prepared in the same

Asymmetric tandem conjugate addition and reaction with carbocations on acylimidazole Michael acceptors

• Brigita Mudráková,
• Renata Marcia de Figueiredo,
• Jean-Marc Campagne and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 881–888, doi:10.3762/bjoc.19.65

• , imines, other Michael acceptors, or alkyl halides. Our group is developing trapping of metal enolates with stabilized carbocations and could show that magnesium enolates generated from enones [22], unsaturated amides [23], or heterocycles reacted with tropylium, dithiolylium or flavylium cations [24

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• ). α-Bromophenylacetic acid amides (4a,b) were prepared from 2-bromo-2-phenylacetyl chloride [38] and the corresponding amine in DCM or toluene at reduced temperature (see Supporting Information File 1). Thiobenzamides and thiobenzanilides were prepared by magnesium chloride-catalyzed thiolysis of

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• were successfully employed in asymmetric conjugate additions (ACA) [3][4][5][6][7][8][9], mainly organozinc [10], Grignard [11][12][13], trialkylaluminum [14], or organozirconium reagents [15]. Additions with these reagents lead to corresponding zinc, magnesium, aluminum, and zirconium enolates, which

• well as ketones were compatible with this process. The chiral ligand L12 afforded the highest enantioselectivities of up to 98% ee (Scheme 12). Conjugate addition of Grignard reagents to coumarin (49) generated the corresponding magnesium enolates 50 [43]. In one instance, this enolate was trapped by

• asymmetric conjugate addition. The magnesium enolates 56 then participated in a copper(II)-mediated intramolecular oxidative coupling to afford benzofused spirocyclic cycloalkanones 57 (Scheme 14) [45]. Our team became interested in domino reactions of metal enolates generated by Cu-catalyzed asymmetric

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• (1 to 5 mol % with regards to furfural). The flow rates of pumps A and B being equal, the concentration of furfural in mixture A was ≈0.7 M and that of all furfural derivatives was 0.35 M in the final mixture. Mixture A was passed through a fixed bed reactor 1 filled with magnesium sulfate. The

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• Wittig reaction led to the α,β-unsaturated ester 87, which was subjected to a hydrogenation reaction in the presence of metallic magnesium, leading to the formation of alkyne 88. The cis-alkene was selectively obtained using the Lindlar catalyst. Finally, hydrolysis of the ester led to the formation of

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

• Robert N. Goldberg,
• Robert T. Giessmann,
• Peter J. Halling,
• Carsten Kettner and
• Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

• number of hydrogen ions produced (or consumed) in the reaction. Thus, if protons are produced or absorbed, the pH will change. A chemical reaction equation must balance all elements including hydrogen, magnesium, and calcium as well as electric charge and has an equilibrium constant denoted by K. An

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• -mediated cross-coupling (77% yield for the coupling step, Scheme 4a) [20]. In this cross-coupling, an α,ω-difunctionalized Grignard reagent bearing a magnesium alkoxide moiety at the end of the aliphatic chain is used as a coupling partner. Following in those footsteps, similar syntheses of other insect

• 1 by the M2i Company. Magnesium alkoxides used as additives Although it can lead to efficient NMP-free cross-coupling procedures, the use of enol phosphates as coupling electrophiles also brings several issues for efficient and sustainable procedures meant to be carried out at large scales. First

• allow the use of alkenyl halides as cross-coupling partners in the absence of NMP. A remarkable feature of the alkyl–dienyl cross-coupling reactions displayed in Scheme 4 is the implication of α,ω-difunctionalized Grignard reagents, bearing a magnesium alkoxide moiety at the end of the chain. Magnesium

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

• metalation of 1,4-dithiins affords stable heteroaryl-magnesium and heteroaryl-zinc-like reagents that can be used in coupling reactions at higher temperatures [43][44]. Dithiin-based dienophiles and their use in synthesis [33][49][50][51][52][53][54]. Dithiin-based dienes and their use in synthesis [55][56

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• polyene 14 (prepared in two steps) in multigram quantities [23]. The reaction employed a divided cell with substoichiometric amounts of magnesium(II) acetate (0.5 equiv) and catalytic copper(II) 3,5-diisopropylsalicylate (0.02 equiv) to allow the redox radical cyclization of polyene in 42% yield. A Tsuji

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• dissolve the magnesium salts, and the organic mixture was the appropriate solvent for the next step. Recently, a regenerated cellulose membrane to purify micelles via inline dialysis was reported by Junkers and co-workers [63]. This semicontinuous closed-loop setup can remove the organic solvent (THF) to a

Synthetic study toward the diterpenoid aberrarone

• Liang Shi,
• Zhiyu Gao,
• Yiqing Li,
• Yuanhao Dai,
• Yu Liu,
• Lili Shi and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173

• –Martin oxidation. At this stage, the pivotal C–H insertion step was tried under the reported conditions [34], and cyclopentenone 8 was successfully obtained. Further study with cross coupling or halogen–magnesium exchange shows this moiety is inert for functional group transformation. The attempt for

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

• Michael Keppler,
• Sandra Moser,
• Henning J. Jessen,
• Christoph Held and
• Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

• fractions [5][10][15][16]. Based on the crystal structures of three PPK2-III, the coordination of polyP and ADP by positively charged amino acids (lysine and arginine) has been suggested [16][17]. Two magnesium ions are held in place by two conserved aspartate residues that further coordinate the polyP and

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• , 70 °C, 24 h, 97% [15]; e) oxalyl chloride, dimethylformamide (cat.), anhydrous dichloromethane, rt, 30 min, then 50 °C, 3 h, AlCl3, anhydrous dichloromethane, 0 °C, 15 min, rt, 15 min, 40 °C, 13 h, 71% [24][43]. Synthesis of thiophene derivative 32: a) Magnesium, 2-ethylhexylbromide, spatula tip

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• solution of sodium hydrogen carbonate, and extracted with ethyl acetate (3 × 50 mL). The organic phase was washed with water (50 mL), brine (30 mL), dried over magnesium sulfate, and concentrated to dryness. A chromatography over silica gel (cyclohexane/ethyl acetate 55:45) at 60 °C gave first compound 4

• brine (30 mL), dried over magnesium sulfate, and concentrated to dryness to give pure compound 3{3,2} (1.64 g, 89%) as a white powder. HRMS (m/z): [M + H]+ calcd for C11H11N2O, 187.0866; found, 187.0867; 1H NMR (DMSO-d6) δ 12.15 (br s, 1H), 7.29–7.25 (m, 5H), 7.22–7.17 (m, 2H), 3.96 (s, 2H); 13C NMR

• sodium hydrogencarbonate was then slowly added to bring the pH to 6, this was extracted with ethyl acetate (3 × 50 mL) and the organic layer was washed with brine (30 mL), dried over magnesium sulfate, and concentrated to dryness. The residue was purified by a chromatography over silica gel (cyclohexane

Synthesis of novel alkynyl imidazopyridinyl selenides: copper-catalyzed tandem selenation of selenium with 2-arylimidazo[1,2-a]pyridines and terminal alkynes

• Mio Matsumura,
• Kaho Tsukada,
• Kiwa Sugimoto,
• Yuki Murata and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 863–871, doi:10.3762/bjoc.18.87

• mixture was diluted with CH2Cl2 (30 mL) and 5% aqueous ammonia (30 mL) at 0 °C. The phases were separated and the aqueous layer was extracted with CH2Cl2 (20 mL × 2). The combined organic layer was washed with 5% aqueous ammonia (30 mL × 3), dried over anhydrous magnesium sulfate, filtered, and

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

• ][38]. Therefore, Gholami and co-workers developed a flow protocol for the synthesis of jasmonal (35) by aldol condensation of heptanal (34) and benzaldehyde (33) utilizing a magnesium-aluminum mixed oxide catalyst in a fixed bed reactor (Scheme 8A) [38]. To suppress the formation of side product 36

• (35) by crossed aldol condensation of benzaldehyde (33) and heptanal (34) in a packed bed reactor containing a magnesium/aluminum mixed oxide catalyst. B) C–H oxidation of ethylbenzene (37) to acetophenone (38) enabled by a MC-system as catalyst and molecular oxygen. BPR = back pressure regulator; MFC