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Search for "magnesium" in Full Text gives 232 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Total synthesis of natural products based on hydrogenation of aromatic rings
- Haoxiang Wu and
- Xiangbing Qi
Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4
- (±)-dihydrolysergic acid (Scheme 11). Smith and co-workers recently reported a six-step synthesis of (±)-lysergic acid [77]. In contrast to previous approaches, the pyridine was introduced via a magnesium–halogen exchange of pyridyl iodide 93, followed by addition to aldehyde 94. Subsequent reduction of the resulting
Graphical Abstract
Scheme 1: The association between dearomatization and natural product synthesis.
Scheme 2: Key challenges in hydrogenation of aromatic rings.
Scheme 3: Hydrogenation of heterocyclic aromatic rings.
Scheme 4: Hydrogenation of the carbocyclic aromatic rings.
Scheme 5: Hydrogenation of the heterocycle part in bicyclic aromatic rings.
Scheme 6: Hydrogenation of the heterocycle part in bicyclic aromatic rings.
Scheme 7: Hydrogenation of benzofuran, indole, and their analogues.
Scheme 8: Hydrogenation of benzofuran, indole, and their analogues.
Scheme 9: Total synthesis of (±)-keramaphidin B by Baldwin and co-workers.
Scheme 10: Total synthesis of (±)-LSD by Vollhardt and co-workers.
Scheme 11: Total synthesis of (±)-dihydrolysergic acid by Boger and co-workers.
Scheme 12: Total synthesis of (±)-lysergic acid by Smith and co-workers.
Scheme 13: Hydrogenation of (−)-tabersonine to (−)-decahydrotabersonine by Catherine Dacquet and co-workers.
Scheme 14: Total synthesis of (±)-nominine by Natsume and co-workers.
Scheme 15: Total synthesis of (+)-nominine by Gin and co-workers.
Scheme 16: Total synthesis of (±)-lemonomycinone and (±)-renieramycin by Magnus.
Scheme 17: Total synthesis of GB13 by Sarpong and co-workers.
Scheme 18: Total synthesis of GB13 by Shenvi and co-workers.
Scheme 19: Total synthesis of (±)-corynoxine and (±)-corynoxine B by Xia and co-workers.
Scheme 20: Total synthesis of (+)-serratezomine E and the putative structure of huperzine N by Bonjoch and co-...
Scheme 21: Total synthesis of (±)-serralongamine A and the revised structure of huperzine N and N-epi-huperzin...
Scheme 22: Early attempts to indenopiperidine core.
Scheme 23: Homogeneous hydrogenation and completion of the synthesis.
Scheme 24: Total synthesis of jorunnamycin A and jorumycin by Stoltz and co-workers.
Scheme 25: Early attempt towards (−)-finerenone by Aggarwal and co-workers.
Scheme 26: Enantioselective synthesis towards (−)-finerenone.
Scheme 27: Total synthesis of (+)-N-methylaspidospermidine by Smith, Grigolo and co-workers.
Scheme 28: Dearomatization approach towards matrine-type alkaloids.
Scheme 29: Asymmetric total synthesis to (−)-senepodine F via an asymmetric hydrogenation of pyridine.
Scheme 30: Selective hydrogenation of indole derivatives and application.
Scheme 31: Synthetic approaches to the oxindole alkaloids by Qi and co-workers.
Scheme 32: Total synthesis of annotinolide B by Smith and co-workers.
Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review
- Daniel S. Müller
Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1
- (Scheme 62B). Systematic optimization studies revealed that additives, such as magnesium bromide etherate or HMPA, had a pronounced impact on both reaction efficiency and stereoselectivity. In 2005, Yan reported that the direct oxidative addition of chloroform to a Mg–TiCl4 bimetallic system generates a
Graphical Abstract
Figure 1: Representative alkenyl chloride motifs in natural products. References: Pinnaic acid [8], haterumalide ...
Figure 2: Representative alkenyl chloride motifs in pharmaceuticals and pesticides. References: clomifene [25], e...
Figure 3: Graphical overview of previously published reviews addressing the synthesis of alkenyl chlorides.
Figure 4: Classification of synthetic approaches to alkenyl chlorides.
Scheme 1: Early works by Friedel, Henry, and Favorsky.
Scheme 2: Product distribution obtained by H NMR integration of crude compound as observed by Kagan and co-wo...
Scheme 3: Side reactions observed for the reaction of 14 with PCl5.
Scheme 4: Only compounds 15 and 18 were observed in the presence of Hünig’s base.
Scheme 5: Efficient synthesis of dichloride 15 at low temperatures.
Scheme 6: Various syntheses of alkenyl chlorides on larger scale.
Scheme 7: Scope of the reaction of ketones with PCl5 in boiling cyclohexane.
Scheme 8: Side reactions occur when using excess amounts of PCl5.
Scheme 9: Formation of versatile β-chlorovinyl ketones.
Scheme 10: Mixture of PCl5 and PCl3 used for the synthesis of 49.
Scheme 11: Catechol–PCl3 reagents for the synthesis of alkenyl chlorides.
Scheme 12: (PhO)3P–halogen-based reagents for the synthesis of alkenyl halides.
Scheme 13: Preparation of alkenyl chlorides from alkenyl phosphates.
Scheme 14: Preparation of alkenyl chlorides by treatment of ketones with the Vilsmeier reagent.
Scheme 15: Preparation of electron-rich alkenyl chlorides by treatment of ketones with the Vilsmeier reagent.
Scheme 16: Cu-promoted synthesis of alkenyl chlorides from ketones and POCl3.
Figure 5: GC yield of 9 depending on time and reaction temperature.
Figure 6: Broken reaction flask after attempts to clean the polymerized residue.
Figure 7: GC yield of 9 depending on the amount of CuCl and time.
Scheme 17: Treatment of 4-chromanones with PCl3.
Scheme 18: Synthesis of alkenyl chlorides from the reaction of ketones with acyl chlorides.
Scheme 19: ZnCl2-promoted alkenyl chloride synthesis.
Scheme 20: Regeneration of acid chlorides by triphosgene.
Scheme 21: Alkenyl chlorides from ketones and triphosgene.
Scheme 22: Various substitution reactions.
Scheme 23: Vinylic Finkelstein reactions reported by Evano and co-workers.
Scheme 24: Challenge of selective monohydrochlorination of alkynes.
Scheme 25: Sterically encumbered internal alkynes furnish the hydrochlorination products in high yield.
Scheme 26: Recent work by Kropp with HCl absorbed on alumina.
Scheme 27: High selectivities for monhydrochlorination with nitromethane/acetic acid as solvent.
Figure 8: Functionalized alkynes which typically afford the monhydrochlorinated products.
Scheme 28: Related chorosulfonylation and chloroamination reactions.
Scheme 29: Reaction of organometallic reagents with chlorine electrophiles.
Scheme 30: Elimination reactions of dichlorides to furnish alkenyl chlorides.
Scheme 31: Elimination reactions of allyl chloride 182 to furnish alkenyl chloride 183.
Scheme 32: Detailed studies by Schlosser on the elimination of dichloro compounds.
Scheme 33: Stereoselective variation caused by change of solvent.
Scheme 34: Elimination of gem-dichloride 189 to afford alkene 190.
Scheme 35: Oxidation of enones to dichlorides and in situ elimination thereof.
Scheme 36: Oxidation of allylic alcohols to dichlorides and in situ elimination thereof.
Scheme 37: Chlorination of styrenes with SOCl2 and elimination thereof.
Scheme 38: Chlorination of styrenes with SOCl2 and elimination thereof.
Scheme 39: Fluorine–chlorine exchange followed by elimination.
Scheme 40: Intercepting cations with alkynes and trapping of the alkenyl cation intermediate with chloride.
Scheme 41: Investigations by Mayr and co-workers.
Scheme 42: In situ activation of benzyl alcohol 230 with BCl3.
Scheme 43: In situ activation of benzylic alcohols with TiCl4.
Scheme 44: In situ activation of benzylic alcohols with FeCl3.
Scheme 45: In situ activation of benzylic alcohols with FeCl3.
Scheme 46: In situ activation of aliphatic chlorides and alcohols with ZnCl2, InCl3, and FeCl3.
Scheme 47: In situ generation of benzylic cations and trapping thereof with alkynes.
Scheme 48: Intramolecular trapping reactions affording alkenyl halides.
Scheme 49: Intramolecular trapping reactions affording alkenyl chlorides.
Scheme 50: Intramolecular trapping reactions of oxonium and iminium ions affording alkenyl chlorides.
Scheme 51: Palladium and nickel-catalyzed coupling reactions to afford alkenyl chlorides.
Scheme 52: Rhodium-catalyzed couplings of 1,2-trans-dichloroethene with arylboronic esters.
Scheme 53: First report on monoselective coupling reactions for 1,1-dichloroalkenes.
Scheme 54: Negishi’s and Barluenga’s contributions.
Scheme 55: First mechanistic investigation by Johnson and co-workers.
Scheme 56: First successful cross-metathesis with choroalkene 260.
Scheme 57: Subsequent studies by Johnson.
Scheme 58: Hoveyda and Schrock’s work on stereoretentive cross-metathesis with molybdenum-based catalysts.
Scheme 59: Related work with (Z)-dichloroethene.
Scheme 60: Further ligand refinement and traceless protection of functional groups with HBpin.
Scheme 61: Alkenyl chloride synthesis by Wittig reaction.
Scheme 62: Alkenyl chloride synthesis by Julia olefination.
Scheme 63: Alkenyl chloride synthesis by reaction of ketones with Mg/TiCl4 mixture.
Scheme 64: Frequently used allylic substitution reactions which lead to alkenyl chlorides.
Scheme 65: Enantioselective allylic substitutions.
Scheme 66: Synthesis of alkenyl chlorides bearing an electron-withdrawing group.
Scheme 67: Synthesis of α-nitroalkenyl chlorides from aldehydes.
Scheme 68: Synthesis of alkenyl chlorides via elimination of an in situ generated geminal dihalide.
Scheme 69: Carbenoid approach reported by Pace.
Scheme 70: Carbenoid approach reported by Pace.
Scheme 71: Ring opening of cyclopropenes in the presence of MgCl2.
Scheme 72: Electrophilic chlorination of alkenyl MIDA boronates to Z- or E-alkenyl chlorides.
Scheme 73: Hydroalumination and hydroboration of alkynyl chlorides.
Scheme 74: Carbolithiation of chloroalkynes.
Scheme 75: Chlorination of enamine 420.
Scheme 76: Alkyne synthesis by elimination of alkenyl chlorides.
Scheme 77: Reductive lithiation of akenyl chlorides.
Scheme 78: Reactions of alkenyl chlorides with organolithium reagents.
Scheme 79: Reactions of alkenyl chlorides with organolithium reagents.
Scheme 80: Addition–elimination reaction of alkenyl chloride 9 with organolithium reagents.
Scheme 81: C–H insertions of lithiumcarbenoids.
Scheme 82: Pd-catalyzed coupling reactions with alkenyl chlorides as coupling partner.
Scheme 83: Ni-catalyzed coupling of alkenylcopper reagent with alkenyl chloride 183.
Scheme 84: Ni-catalyzed coupling of heterocycle 472 with alkenyl chloride 473.
Scheme 85: Synthesis of α-chloroketones by oxidation of alkenyl chlorides.
Scheme 86: Tetrahalogenoferrate(III)-promoted oxidation of alkenyl chlorides.
Scheme 87: Chlorine–deuterium exchange promoted by a palladium catalyst.
Scheme 88: Reaction of alkenyl chlorides with thiols in the presence of AIBN (azobisisobutyronitrile).
Scheme 89: Chloroalkene annulation.
Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds
- Natalya Akhmetdinova,
- Ilgiz Biktagirov and
- Liliya Kh. Faizullina
Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185
- 111 led to (±)-preterrenoid (107) with 68% yield, which was subjected to stereoselective oxidation with magnesium monoperoxyphthalate (MMPP) to give (±)-terrenoid (108) as a single diastereomer. Subsequent treatment of the key precursor 108 with catalytic amounts of NaOMe in MeOH resulted in
Graphical Abstract
Scheme 1: Ozonolysis–cyclization sequence in the synthesis of echinopine A (3).
Scheme 2: Ozonolysis–cyclization sequence in the synthesis of taiwaniaquinoids 7–12.
Figure 1: Iridoid skeleton.
Scheme 3: Ozonolysis–cyclization sequence in the synthesis of compounds 17a,b, 18 and 19 with iridoid topolog...
Scheme 4: Oxidation–aldol condensation sequence in the synthesis of compounds 21 and 23 with iridoid topology....
Scheme 5: Oxidation–aldol condensation sequence in the synthesis of compounds 29 and 30 with iridoid topology....
Scheme 6: Method for ring contraction in the absence of a double bond in a six-membered ring of triterpenoids....
Scheme 7: Oxidation–Dieckmann cyclization sequence in the synthesis of a new nortriterpenoid 39.
Scheme 8: Oxidation–Dieckmann cyclization sequence in the synthesis of 18,19-di-nor-cholesterol (40).
Scheme 9: Oxidation–cyclization sequence in the synthesis of 3-ethyl-substituted betulinic acid derivatives 49...
Scheme 10: Benzilic acid-type rearrangement in the synthesis of 4β-acetoxyprobotryane-9β,15α-diol (52).
Scheme 11: Benzilic acid-type rearrangement in the synthesis of (−)-taiwaniaquinone H (11).
Scheme 12: Benzilic acid-type rearrangement in the synthesis of dactylicapnosines A (63) and B (64).
Scheme 13: Aza-benzilic acid-type rearrangement in the synthesis of (+)-stephadiamine (71).
Scheme 14: α-Ketol rearrangement in the synthesis of saffloneoside (73).
Scheme 15: Conversion of (−)-preaustinoid A (80) to (−)-preaustinoid B (81) via α-ketol rearrangement.
Scheme 16: α-Ketol rearrangement in the synthesis of 2,8-oxymethano-bridged diquinane 90.
Scheme 17: Oxidative ring contraction during the synthesis of (+)-cuparene (91) and (+)-tochuinylacetate (92).
Scheme 18: Semipinacol rearrangement in the synthesis of diterpenoids 97–100.
Scheme 19: Co-catalyzed homoallyl-type rearrangement in the syntheses of meroterpenes 106–109.
Scheme 20: Ring contraction reaction promoted by TTN·3H2O and HTIB in the synthesis of indanes.
Scheme 21: Rearrangement involving a hypervalent iodine compound in the synthesis of derivative 120.
Scheme 22: Wolff rearrangement in the synthesis of taiwaniaquinones A (7), F (8), taiwaniaquinols B (10), D (1...
Scheme 23: Wolff rearrangement in the synthesis of cheloviolene C (128), seconorrisolide B (129), and seconorr...
Scheme 24: Wolff rearrangement in the synthesis of (−)-pavidolide B (134).
Scheme 25: Wolff rearrangement in the synthesis of presilphiperfolan-8-ol (141).
Scheme 26: Photochemical rearrangement in the synthesis of cyclopentane derivatives 147a,b.
Scheme 27: Synthesis of cyclopentane derivatives 147a and 151.
Scheme 28: Photochemical rearrangement in the synthesis of cyclopentane derivative 153.
Scheme 29: Photochemical rearrangement in the synthesis of tricyclic ketones 155, 156.
Scheme 30: Photochemical rearrangement in the synthesis of cis/trans salts 160.
Figure 2: Scope of the photoinduced carboborative ring contraction of steroids. Reaction conditions: steroid ...
Scheme 31: Photoinduced carboborative ring contraction in the synthesis of artalbic acid (180).
Scheme 32: Synthetic versatility of the photoinduced carboborative ring contraction.
Scheme 33: Methods of disclosure of epoxide 189.
Scheme 34: Methods of disclosure of epoxide 190.
Scheme 35: Rearrangement of α,β-epoxy ketone 197.
Scheme 36: Acid-induced rearrangement in the synthesis of perhydrindane ketones 202 and 205.
Scheme 37: Rearrangement of epoxyketone 208 in the synthesis of huperzine Q (206).
Scheme 38: Rearrangement of epoxide 212 under the action of Grignard reagent.
Scheme 39: Semipinacol rearrangement of epoxide 220 in the synthesis of (−)-citrinadin A (217) and (+)-citrina...
Scheme 40: Semipinacol rearrangement of epoxide 225 in the synthesis of hamigeran G (223).
Scheme 41: Semipinacol rearrangement of epoxide 231 in the synthesis of (−)-spirochensilide A (228).
Scheme 42: Wagner–Meerwein rearrangement in the synthesis of compound 234 with iridoid topology.
Scheme 43: Wagner–Meerwein rearrangement in the synthesis of compound 238 with iridoid topology.
Scheme 44: Wagner–Meerwein rearrangement in the synthesis of compound 241 with iridoid topology.
Scheme 45: Wagner–Meerwein rearrangement in the synthesis of lupane derivatives 245, 246, 248, and 249.
Scheme 46: Wagner–Meerwein rearrangement in the synthesis of weisaconitine D (252) and cardiopetaline (255).
Scheme 47: Wagner–Meerwein rearrangement in the synthesis of cardiopetaline (255).
Halogenated butyrolactones from the biomass-derived synthon levoglucosenone
- Johannes Puschnig,
- Martyn Jevric and
- Ben W. Greatrex
Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175
- dichloro-magnesium enolates to protected ᴅ-glyceraldehyde [11]. In 1988, Hertel et al. from the Lilly laboratories published the first synthesis of the clinically important anticancer agent gemcitabine, using an intermediate γ-butyrolactone constructed using protected ᴅ-glyceraldehyde and ethyl
Graphical Abstract
Figure 1: Halogen-containing butyrolactone-derived bioactives.
Scheme 1: Preparation of chlorinated and brominated lactones 8a,b and 11a,b.
Scheme 2: Preparation of fluorinated lactone 14.
Scheme 3: Fluorination of LGO (5) and conversion to lactone 17.
Scheme 4: Trifluoromethylation of 9a,b and 15 and subsequent Baeyer–Villiger oxidation.
Enantioselective radical chemistry: a bright future ahead
- Anna C. Renner,
- Sagar S. Thorat,
- Hariharaputhiran Subramanian and
- Mukund P. Sibi
Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174
- occurred in an anti fashion. Products were obtained with up to 97% ee via catalysis by complexes of magnesium or copper(II) with ligand L1. The absolute stereochemistry of the product could be controlled by a simple change from copper(II) to magnesium Lewis acids while using the same chiral ligand, thus
Graphical Abstract
Figure 1: Methods of radical generation (A) and general types of radical reactions (B).
Figure 2: Chiral catalysis in enantioselective radical chemistry [13-37].
Scheme 1: Diastereo- and enantioselective additions of nucleophilic radicals to N-enoyloxazolidinone and pyrr...
Scheme 2: Organocatalyzed formal [3 + 2] cycloadditions affording substituted pyrrolidines.
Scheme 3: Synthesis of a hexacyclic compound via an organocatalyzed enantioselective polyene cyclization.
Scheme 4: Nickel-catalyzed asymmetric cross-coupling reactions.
Scheme 5: Chiral cobalt–porphyrin metalloradical-catalyzed radical cyclization reactions.
Scheme 6: Enantioselective radical chaperone catalysis.
Scheme 7: Enantioselective radical addition by decatungstate/iminium catalysis.
Scheme 8: An ene-reductase-catalyzed photoenzymatic enantioselective radical cyclization/enantioselective HAT...
Scheme 9: Photoenzymatic oxidative C(sp3)–C(sp3) coupling reactions between organoboron compounds and amino a...
Scheme 10: Electrochemical α-alkenylation reactions of 2-acylimidazoles catalyzed by a chiral-at-rhodium Lewis...
Scheme 11: Regio- and enantioselective electrochemical reactions of silyl polyenolates catalyzed by a chiral n...
α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions
- Vladyslav O. Honcharov,
- Yana I. Sakhno,
- Olena H. Shvets,
- Vyacheslav E. Saraev,
- Svitlana V. Shishkina,
- Tetyana V. Shcherbakova and
- Valentyn A. Chebanov
Beilstein J. Org. Chem. 2025, 21, 2021–2029, doi:10.3762/bjoc.21.157
- with the addition of 0.1% formic acid. The use of other eluents such as acetonitrile and different ratios of hexane/ethyl acetate, dichloromethane/methanol as well as the application of methods for the isolation of triphenylphosphine oxide by complexation with calcium and magnesium salts [54][55] or
Graphical Abstract
Figure 1: Some biologically active quinoxalinone derivatives.
Scheme 1: Known multicomponent reactions of KGA.
Scheme 2: Ugi reaction involving KGA.
Scheme 3: Tandem Ugi/aza-Wittig combination involving KGA.
Figure 2: Molecular structure of 3-(4-(2-(tert-butylamino)-1-(4-methoxyphenyl)-2-oxoethyl)-5,7-dimethyl-3-oxo...
Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines
- Margherita Gazzotti,
- Fabrizio Medici,
- Valerio Chiroli,
- Laura Raimondi,
- Sergio Rossi and
- Maurizio Benaglia
Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147
- represent the most established approach to imino-pinacol coupling (Scheme 1), with zero-valent metals traditionally employed as reductants and various strategies extensively explored [2]. The use of alkali metals [3][4][5], as lithium and sodium, and alkaline earth metals [6], as magnesium, are
Graphical Abstract
Scheme 1: Synthesis of vicinal diamines via imino-pinacol coupling in the presence of metal-based reductants.
Scheme 2: Light-promoted imino-pinacol coupling for the synthesis of vicinal diamines.
Scheme 3: Historical perspective on electrochemical imino-coupling protocols.
Scheme 4: Stereoselective electroreductive intramolecular imino-pinacol reaction.
Scheme 5: Scope of the imino-pinacol coupling reaction. Reaction conditions: GC electrodes, NEt4BF4 (2.6 equi...
Figure 1: X-ray determined structure of chiral piperazine 2b.
Scheme 6: Continuous flow synthesis of piperazine 2a. The yield was determined by 1H NMR spectroscopy using 1...
Scheme 7: Proposed reaction mechanism.
Scheme 8: Cyclic voltammetry investigation. Cyclic voltammetry of a 0.325 M solution of Et4NBF4 in DMF (light...
Transition-state aromaticity and its relationship with reactivity in pericyclic reactions
- Israel Fernández
Beilstein J. Org. Chem. 2025, 21, 1613–1626, doi:10.3762/bjoc.21.125
- process occurs in a concerted manner through the corresponding five-membered transition state, the germanium and magnesium cyaphide complexes are significantly more reactive (i.e., leading to a lower-barrier process, ΔG≠ ≈ 20 kcal/mol) than their platinum or gold counterparts, which exhibit barriers
- interaction derives from both electrostatic and orbital interactions, which are markedly more stabilizing for the process involving the magnesium cyaphide complex. The stronger electrostatic interactions mainly result from the significant polarization of the cyaphide ligand induced by the highly
- electropositive magnesium atom whereas the stronger orbital interactions derive from a more stabilizing direct π(C≡P)→π*(azide) molecular orbital interaction coupled with a stronger reverse π(azide)→π*(C≡P) interaction. Conclusion Through selected representative examples, in this perspective article the interplay
Graphical Abstract
Scheme 1: (a) Diels–Alder cycloaddition reaction between butadiene and ethylene. (b) Gold(I)-catalyzed propar...
Figure 1: Transition states computed for the Diels–Alder cycloaddition reaction between isoprene and methyl a...
Figure 2: Comparative activation strain analyses (a) and energy decomposition analysis (b) of the Diels–Alder...
Figure 3: (a) Evolution of the NICS(3, +1) values along a z-axis perpendicular to the molecular plane of the ...
Figure 4: Comparative activation strain analyses (a) and energy decomposition analysis (b) of the carbonyl–en...
Figure 5: AICD (a) and EDDB (b) plots for the transition state involved in the DGRT between ethene and ethane....
Figure 6: Comparative activation strain analyses (a) and energy decomposition analysis (b) of the DGRT betwee...
Scheme 2: Representative cycloisomerization reaction of 1,3-hexadien-5-yne.
Figure 7: AICD plots of the transition states associated with the Hopf cyclization reactions involving cis-he...
Figure 8: Comparative activation strain analyses of the Hopf cyclization involving ene–ene–ynes E=CH–CH=CH–C≡...
Scheme 3: 1,3-Dipolar cycloaddition reactions between t-BuN3 and cyaphide complexes.
Figure 9: Evolution of the NICS(3, +1) values along a z-axis perpendicular to the molecular plane of the TSs ...
Figure 10: Comparative activation strain analyses (a) and energy decomposition analysis (b) of the 1,3-dipolar...
Synthetic approach to borrelidin fragments: focus on key intermediates
- Yudhi Dwi Kurniawan,
- Zetryana Puteri Tachrim,
- Teni Ernawati,
- Faris Hermawan,
- Ima Nurasiyah and
- Muhammad Alfin Sulmantara
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- 124 was obtained by reaction with magnesium in anhydrous diethyl ether. Herber and Breit emphasized that activating the magnesium using a dry stirring method was crucial for smooth magnesiation. The freshly prepared Grignard reagent 124 was added to the allyl electrophile (R)-120 in the presence of
- subsequent transmetallation with MgBr2·OEt2 yielded the desired magnesium species. Reaction of this reagent with (R)-120 in the presence of CuBr·SMe2 afforded product (–)-128 in 86% yield, with perfect regioselectivity (>99:1) and excellent stereochemistry (98:2 dr). Repeating the sequence of ozonolysis
Graphical Abstract
Figure 1: Chemical structure of borrelidin (1).
Scheme 1: Synthetic strategy for Morken’s C2–C12 intermediate 20 as reported by Uguen et al. [41].
Scheme 2: Preparation of monoacetates 37 and ent-38 by Uguen et al. [41].
Scheme 3: Preparation of sulfones 27 and ent-27 by Uguen et al. [41].
Scheme 4: Attempts to couple sulfones 27 and ent-27 with epoxides 23a–c reported by Uguen et al. [41].
Scheme 5: Modified synthetic plan for Morken’s C2–C12 intermediate by Uguen [41].
Scheme 6: Revised synthetic strategy for Morken’s C2–C12 intermediate 20 by Uguen [41].
Scheme 7: Iterative synthesis of polydeoxypropionates developed by Zhou et al. [40].
Scheme 8: Application of iterative synthesis of polydeoxypropionate to construct the C3–C11 fragment 60 of bo...
Scheme 9: Retrosynthetic analysis of borrelidin by Yadav et al. [39].
Scheme 10: Two-carbon homologation of precursor 66 in the synthesize C1–C11 fragment 61 of borrelidin [39].
Scheme 11: Synthesis of the C1–C11 fragment 61 of borrelidin from monoalcohol 65 [39].
Scheme 12: Synthetic plan for Theodorakis’ C3–C11 fragment 82 of borrelidin by Laschat et al. [38].
Scheme 13: Synthesis of Theodorakis’ C3–C11 fragment 82 from compound 88 [38].
Scheme 14: Retrosynthesis of 61 and 62b by Minnaard and Madduri [37].
Scheme 15: Synthesis of intermediate 98 by Minnaard and Madduri [37].
Scheme 16: Synthesis of Ōmura’s C1–C11 fragment 61 by Minnaard and Madduri [37].
Scheme 17: Synthesis of fragment 62b of borrelidin as proposed by Minnaard and Madduri [37].
Scheme 18: Iterative directed allylation for the synthesis of deoxypropionates by Herber and Breit [33].
Scheme 19: Iterative copper-mediated directed allyl substitution for the synthesis of Theodorakis’ C3–C11 frag...
Scheme 20: Retrosynthesis of the C3–C17 fragment of borrelidin by Iqbal and co-workers [35].
Scheme 21: Synthesis of key intermediates 137 and 147 for the synthesis of the C3–C17 fragment of borrelidin.
Scheme 22: Synthesis of the C3–C17 fragment 150a,b of borrelidin.
Scheme 23: Synthesis of the C11–C15 fragment 155a of borrelidin.
Scheme 24: Macrocyclization of borrelidin model compounds 155a and 155b using ring-closing metathesis.
Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA
- Raphael Bereiter and
- Ronald Micura
Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56
- containing potassium and magnesium ions at a physiological pH of 7.0 for 5 hours. Analysis of the reaction mixture by anion-exchange HPLC revealed that the bromopropyl handle (C3 homolog 8) gave the highest yield of covalently tethered HBC-RNA complex (50%). Significantly less RNA alkylation yield was
Graphical Abstract
Figure 1: Structure-guided approach for engineering the (non-covalent) fluorescent light-up aptamer Pepper in...
Scheme 1: Chemical structures of the HBC dye family [7]. Variations to HBC530 highlighted in red color. All dyes...
Scheme 2: Synthesis of bromoalkyl HBC derivatives 7, 8, and 9.
Scheme 3: Synthesis of the HBC ether derivative 11.
Figure 2: Pepper aptamer reacts with different HBC derivatives. Chemical structures of the HBC derivatives us...
Scheme 4: Derivatization of the HBC fluorophore 5 to generate handles with distinct electrophilic groups.
Scheme 5: Synthesis of mesylated HBC fluorophores 16, 17, and 18.
Scheme 6: Synthesis of the bifunctional HBC fluorophore 22. For an application of 22 (pulldown of circular Pe...
Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt
- Yasushi Yoshida,
- Maho Aono,
- Takashi Mino and
- Masami Sakamoto
Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43
- tetrasubstituted carbon stereogenic centers [42][43][44][45][46]. In 2011, Shibasaki, Matsunaga and co-workers reported strontium or magnesium-catalyzed stereodivergent asymmetric Mannich reactions of an α-isothiocyanato ester with ketimines, which provided the products in excellent yields and
Graphical Abstract
Figure 1: Selected examples and applications of chiral halogen-bonding catalysts.
Figure 2: Selected examples for the construction of contiguous tetrasubstituted carbon centers via the Mannic...
Scheme 1: Catalyst screening for the asymmetric Mannich reaction. All yields were determined by 1H NMR spectr...
Scheme 2: N-Protecting group optimization for the asymmetric Mannich reaction. All yields were determined by 1...
Scheme 3: Catalyst screening using 7b as a substrate. All yields were determined by 1H NMR spectroscopy using...
Scheme 4: Substrate scope for the asymmetric Mannich reaction using 0.06 mmol of 7. Isolated product yields a...
Figure 3: Plausible reaction mechanism.
Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene
- Long K. San,
- Sebastian Balser,
- Brian J. Reeves,
- Tyler T. Clikeman,
- Yu-Sheng Chen,
- Steven H. Strauss and
- Olga V. Boltalina
Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39
- (trifluoromethyl)benzene (1,4-C6H4(CF3)2, Central Glass Co., 99%); dimethyl sulfoxide (DMSO, Fisher Scientific, ACS grade); anhydrous magnesium sulfate (MgSO4, Fisher Scientific); Cu powder (Strem Chemicals, 99%); dichloromethane (EMD Chemicals, ACS grade); acetone (technical grade); THF (Aldrich/Merck, ACS grade
Graphical Abstract
Scheme 1: List of reactions, experimental conditions and yields studied in this work.
Figure 1: Top: 379 MHz 19F NMR spectrum of 9,10-ANTH(BnF)2 in CDCl3. Bottom: absorption (aerobic, solid line)...
Figure 2: Top: X-ray structure of 9,10-ANTH(BnF)2, thermal ellipsoids 50% probability. Bottom: a view down th...
Figure 3: Absorption spectra of ANTH and 9,10-ANTH(BnF)2 in CH2Cl2 recorded over the period of 53 days in air...
Figure 4: Direct analysis in real time (DART) positive ion mass spectrum of the photoirradiated 9,10-ANTH(BnF)...
Figure 5: The % remaining of ANTH and 9,10-ANTH(BnF)2 dissolved in CDCl3 upon irradiation. Resonances δ = 7.4...
Synthesis of electrophile-tethered preQ1 analogs for covalent attachment to preQ1 RNA
- Laurin Flemmich and
- Ronald Micura
Beilstein J. Org. Chem. 2025, 21, 483–489, doi:10.3762/bjoc.21.35
- methanol (1.3 mL). Anhydrous magnesium sulfate (340 mg, 2.82 mmol, 10 equiv) and the respective amino alcohol (2.82 mmol, 10 equiv) were added. The mixture was sonicated for 30 minutes and subsequently stirred at room temperature for 16 h. After cooling to 0 °C, sodium borohydride (96.1 mg, 2.54 mmol, 9
Graphical Abstract
Scheme 1: A) Chemical structures of hypermodified nucleobase queuine and nucleoside queuosine (Q) occurring a...
Scheme 2: Three-step syntheses of preQ1 (1) and DPQ1 (2). For the synthesis of m6preQ1 (16) see Supporting Information File 1.
Scheme 3: Syntheses of haloalkyl- and mesyloxyalkyl-modified preQ1 as and DPQ1 ligands.
Red light excitation: illuminating photocatalysis in a new spectrum
- Lucas Fortier,
- Corentin Lefebvre and
- Norbert Hoffmann
Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22
- four compared to batch processes using conventional solvents. Recent advances have demonstrated that naturally derived photocatalysts, such as chlorophyll, a magnesium-based chlorin complex, can also efficiently drive photocatalytic transformations. In the study by Ouyang et al. chlorophyll extracted
Graphical Abstract
Figure 1: Influence of the metal center M (Fe, Ru, Os) on the position of the MLCT and MC (metal-centered) ab...
Scheme 1: Red-light-mediated ring-closing metathesis through activation of a ruthenium catalyst by an osmium ...
Scheme 2: Photocatalyzed polymerization of dicylopentadiene mediated with red or blue light.
Figure 2: Comparison between [Ru(bpy)3]2+ and [Os(tpy)2]2+ in a photocatalyzed trifluoromethylation reaction:...
Scheme 3: Red-light photocatalyzed C–N cross-coupling reaction by T. Rovis et al. (SET = single-electron tran...
Figure 3: Red-light-mediated aryl oxidative addition with a bismuthinidene complex.
Scheme 4: Red-light-mediated reduction of aryl derivatives by O. S. Wenger et al. (PC = photocatalyst, anh = ...
Scheme 5: Red-light-mediated aryl halides reduction with an isoelectronic chromium complex (TDAE = tetrakis(d...
Scheme 6: Red-light-photocatalyzed trifluoromethylation of styrene derivatives with Umemoto’s reagent and a p...
Scheme 7: Red-light-mediated energy transfer for the cross-dehydrogenative coupling of N-phenyltetrahydroisoq...
Scheme 8: Red-light-mediated oxidative cyanation of tertiary amines with a phthalocyanin zinc complex.
Scheme 9: Formation of dialins and tetralins via a red-light-photocatalyzed reductive decarboxylation mediate...
Scheme 10: Oxidation of β-citronellol (28) via energy transfer mediated by a red-light activable silicon phtha...
Scheme 11: Formation of alcohol derivatives 32 from boron compounds 31 using chlorophyll (chl) as a red-light-...
Scheme 12: Red-light-driven reductive dehalogenation of α-halo ketones mediated by a thiaporphyrin photocataly...
Figure 4: Photoinduced electron transfer-reversible addition-fragmentation chain transfer polymerization medi...
Figure 5: Recent examples of red-light-mediated photocatalytic reactions with traditional organic dyes.
Figure 6: Squaraine photocatalysts used by Goddard et al. and aza-Henry reaction with squaraine-based photoca...
Figure 7: Reactions described by Goddard et al. involving 40 as the photocatalyst.
Figure 8: Various structures of squaraine derivatives used to initiate photopolymerizations.
Figure 9: Naturally occurring cyanins.
Figure 10: Influence of the structure on the photophysical properties of a cyanin dye.
Figure 11: NIR-light-mediated aza-Henry reaction photocatalyzed by 46.
Scheme 13: Photocatalyzed arylboronic acids oxidation by 46.
Figure 12: Cyanin structures synthetized and characterized by Goddard et al. (redox potentials given against s...
Figure 13: N,N′-Di-n-propyl-1,13-dimethoxyquinacridinium (55) with its redox potentials at its ground state an...
Scheme 14: Dual catalyzed C(sp2)–H arylation of 57 using DMQA 55 as the red-light-absorbing photocatalyst.
Scheme 15: Red-light-mediated aerobic oxidation of arylboronic acids 59 into phenols 60 via the use of DMQA as...
Figure 14: Red-light-photocatalyzed reactions proposed by Gianetti et al. using DMQA as the photocatalyst.
Scheme 16: Simultaneous release of NO and production of superoxide (O2•−) and their combination yielding the p...
Figure 15: Palladium porphyrin complex as the photoredox catalyst and the NO releasing substrate are linked in...
Scheme 17: Uncaging of compound 69 which is a microtubule depolymerizing agent using near IR irradiation. The ...
Scheme 18: Photochemical uncaging of drugs protected with a phenylboronic acid derivative using near IR irradi...
Scheme 19: Photoredox catalytical generation of aminyl radicals with near IR irradiation for the transfer of b...
Scheme 20: Photoredox catalytical fluoroalkylation of tryptophan moieties.
Figure 16: Simultaneous absorption of two photons of infrared light of low energy enables electronic excitatio...
Scheme 21: Uncaging Ca2+ ions using two-photon excitation with near infrared light.
Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts
- Mandeep K. Chahal
Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257
- functional versatility [44], and many of these resulting metal complexes are catalytically active [45][46][47]. These synthetic metalloporphyrins take inspiration from biological systems, such as hemes (iron complexes), chlorophylls (magnesium complexes), and vitamin B12 (cobalt complex). Contrary to
Graphical Abstract
Figure 1: Chemical structures of the main tetrapyrrolic macrocycles studied in this review for their role as ...
Figure 2: Calix[4]pyrroles 3 and 4 and an their acyclic analogue 5 used for the transformation of Danishefsky...
Figure 3: Calixpyrrole-based organocatalysts 11 and 12 for the diastereoselective addition reaction of TMSOF ...
Figure 4: (a) Chemical structures of macrocyclic organocatalysts used for the synthesis of cyclic carbonates ...
Figure 5: Cuprous chloride-catalyzed aziridination of styrene (22) by chloramine-T (23) providing 1-tosyl-2-p...
Figure 6: Chemical structures of the various porphyrin macrocycles (18, 25–41) screened as potential catalyst...
Figure 7: Organocatalytic activity of distorted porphyrins explored by Senge and co-workers. Planar macrocycl...
Figure 8: Chemical structures of H2EtxTPP (x = 0, 2, 4, 6, 8) compounds with incrementally increasing nonplan...
Figure 9: Chemical structures of OxP macrocycles tested as potential organocatalysts for the conjugate additi...
Figure 10: a) Fundamental structure of the J-aggregates of diprotonated TPPS3 53 and b) its use as a catalyst ...
Figure 11: Chemical structures of amphiphilic porphyrin macrocycles used as pH-switchable catalysts based on i...
Figure 12: a) Chemical structures of porphyrin macrocycles for the cycloaddition of CO2 to N-alkyl/arylaziridi...
Figure 13: Electron and energy-transfer processes typical for excited porphyrin molecules (Por = porphyrin mac...
Figure 14: Proposed mechanism for the light-induced α-alkylation of aldehydes with EDA in the presence of H2TP...
Figure 15: a) Chemical structures of porphyrins screened as photoredox catalysts, b) model reaction of furan (...
Figure 16: Porphyrin macrocycles H2TPP (18) and PPIX 78 as photoreductants for the red light-induced C–H aryla...
Figure 17: Porphyrin macrocycles H2TPP (18) and PPIX 78 as photoredox catalyst for (a) α-alkylation of an alde...
Figure 18: Corrole macrocycles 98–100 as photoredox catalysts for C–H arylation and borylation reactions. Adap...
Figure 19: Proposed catalytic cycle of electrocatalytic generation of H2 evolution using tetrapyrrolic macrocy...
Figure 20: a) Chemical structures of tetrapyrrolic macrocycles 109, 73, and 110 used for oxygen reductions in ...
Figure 21: a) Absorption spectra (left) of the air-saturated DCE solutions containing: 5 × 10−5 M H2TPP (black...
Figure 22: Chemical structures of N,N’-dimethylated saddle-distorted porphyrin isomers, syn-Me2P 111 and anti-...
Figure 23: Reaction mechanisms for the two-electron reduction of O2 by a) syn-Me2Iph 113 and b) anti-Me2Iph 114...
Figure 24: O2/H2O2 interconversion using methylated saddle-distorted porphyrin and isophlorin (reduced porphyr...
Figure 25: Chemical structures of distorted dodecaphenylporphyrin macrocycle 117 and its diprotonated form 118...
Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates
- Kento Iwai,
- Akari Hikasa,
- Kotaro Yoshioka,
- Shinki Tani,
- Kazuto Umezu and
- Nagatoshi Nishiwaki
Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238
- , the molecular sieves were filtered off, and the filtrate was washed with water (50 mL × 2). The organic layer was dried over magnesium sulfate and concentrated under reduced pressure to afford diethyl α-acetoxy-α-(4-methylbenzoylamino)malonate (1a, 2.86 g, 8.1 mmol, 81% yield) as white solid. When
Graphical Abstract
Scheme 1: Synthesis of polyfunctionalized methane derivatives through successive nucleophilic additions to th...
Scheme 2: Cyclization of 4a quenched by D2O.
Scheme 3: Plausible mechanisms for the ring closure of 4.
Scheme 4: Hydration of the ethynyl group of 4a.
A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis
- Nian Li,
- Ruzal Sitdikov,
- Ajit Prabhakar Kale,
- Joost Steverlynck,
- Bo Li and
- Magnus Rueping
Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214
Graphical Abstract
Figure 1: Classification of LSF reactions in this review.
Scheme 1: C(sp2)–H trifluoromethylation of heteroarenes.
Scheme 2: C(sp2)–H and C(sp3)–H alkylation of complex molecules.
Scheme 3: Electrochemical oxidation-induced intermolecular aromatic C–H sulfonamidation.
Scheme 4: Bioconjugation of tyrosine with (a) phenothiazine and (b) urazole derivatives.
Scheme 5: Electrochemical iodoamination of indoles using unactivated amines.
Scheme 6: Allylic C(sp3)–H aminations with sulfonamides.
Scheme 7: Electrochemical benzylic oxidation of C–H bonds.
Scheme 8: Site-selective electrooxidation of methylarenes to aromatic acetals.
Scheme 9: Electrochemical activation of C–H by electron-deficient W2C nanocrystals.
Scheme 10: α-Acyloxy sulfide preparation via C–H/OH cross-dehydrogenative coupling.
Scheme 11: Aromatic C–H-bond thiolation.
Scheme 12: C(sp2)–H functionalization for the installation of sulfonamide groups.
Scheme 13: Preparation of (hetero)aryl chlorides and vinyl chloride with 1,2-dichloroethane. aCu(OAc)2 (0.05 e...
Scheme 14: Electrochemical dual-oxidation enables access to α-chlorosulfoxides.
Scheme 15: Regio- and chemoselective formyloxylation–bromination/chlorination/trifluoromethylation of alkenes.
Scheme 16: Aziridine formation by coupling amines and alkenes.
Scheme 17: Formation of iminosulfide ethers via difunctionalization of an isocyanide.
Scheme 18: Synthesis of 1,3-difunctionalized molecules via C–C-bond cleavage of arylcyclopropane.
Scheme 19: Electrooxidative amino- and oxyselenation of alkenes. VBImBr = 1-butyl-3-vinylimidazolium bromide.
Scheme 20: Electrooxidative dehydrogenative [4 + 2] annulation of indole derivatives.
Scheme 21: Electrochemical cyclization combined with alkoxylation of triticonazole.
Scheme 22: Electrochemically tuned oxidative [4 + 2] annulation of olefins with hydroxamic acids.
Scheme 23: Electrosynthesis of indole derivatives via cyclization of 2-ethynylanilines.
Scheme 24: Allylic C–H oxidation of mono-, di-, and sesquiterpenes.
Scheme 25: Oxidation of unactivated C–H bonds.
Scheme 26: Fluorination of C(sp3)–H bonds. rAP = rapid alternating polarity.
Scheme 27: C(sp3)–H α-cyanation of secondary piperidines.
Scheme 28: Selective electrochemical hydrolysis of hydrosilanes to silanols.
Scheme 29: Organocatalytic electrochemical amination of benzylic C–H bonds.
Scheme 30: Iodide ion-initiated anodic oxidation reactions.
Scheme 31: Mn(III/IV) electro-catalyzed C(sp3)–H azidation.
Scheme 32: Tailored cobalt–salen complexes enable electrocatalytic intramolecular allylic C–H functionalizatio...
Scheme 33: Cobalt–salen complexes-induced electrochemical (cyclo)additions.
Scheme 34: Electrochemical 1,2-diarylation of alkenes enabled by direct dual C–H functionalization of electron...
Scheme 35: Cobalt-electrocatalyzed atroposelective C–H annulation.
Scheme 36: Nickel-electrocatalyzed C(sp2)–H alkoxylation with secondary alcohols.
Scheme 37: Nickel-catalyzed electrochemical enantioselective amination.
Scheme 38: Ruthenium-electrocatalyzed C(sp2)–H mono- and diacetoxylation.
Scheme 39: Rhodium(III)-catalyzed aryl-C–H phosphorylation enabled by anodic oxidation-induced reductive elimi...
Scheme 40: Asymmetric Lewis-acid catalysis for the synthesis of non-racemic 1,4-dicarbonyl compounds.
Scheme 41: Electrochemical enantioselective C(sp3)–H alkenylation.
Scheme 42: Palladium-catalyzed electrochemical dehydrogenative cross-coupling.
Scheme 43: Ir-electrocatalyzed vinylic C(sp2)–H activation for the annulation between acrylic acids and alkyne...
Scheme 44: Electrochemical gold-catalyzed C(sp3)–C(sp) coupling of alkynes and arylhydrazines.
Scheme 45: Photoelectrochemical alkylation of C–H heteroarenes using organotrifluoroborates.
Scheme 46: Mn-catalyzed photoelectro C(sp3)–H azidation.
Scheme 47: Photoelectrochemical undirected C–H trifluoromethylations of (Het)arenes.
Scheme 48: Photoelectrochemical dehydrogenative cross-coupling of heteroarenes with aliphatic C–H bonds.
Scheme 49: C–H amination via photoelectrochemical Ritter-type reaction.
Scheme 50: Photoelectrochemical multiple oxygenation of C–H bonds.
Scheme 51: Accelerated C(sp3)–H heteroarylations by the f-EPC system.
Scheme 52: Photoelectrochemical cross-coupling of amines.
Scheme 53: Birch electroreduction of arenes. GSW = galvanized steel wire.
Scheme 54: Electroreductive deuterations.
Scheme 55: Chemoselective electrosynthesis using rapid alternating polarity.
Scheme 56: Electroreductive olefin–ketone coupling.
Scheme 57: Electroreductive approach to radical silylation.
Scheme 58: Electrochemical borylation of alkyl halides. CC = carbon close.
Scheme 59: Radical fluoroalkylation of alkenes.
Scheme 60: Electrochemical defluorinative hydrogenation/carboxylation.
Scheme 61: Electrochemical decarboxylative olefination.
Scheme 62: Electrochemical decarboxylative Nozaki–Hiyama–Kishi coupling.
Scheme 63: Nickel-catalyzed electrochemical reductive relay cross-coupling.
Scheme 64: Electrochemical chemo- and regioselective difunctionalization of 1,3-enynes.
Scheme 65: Electrocatalytic doubly decarboxylative crosscoupling.
Scheme 66: Electrocatalytic decarboxylative crosscoupling with aryl halides.
Scheme 67: Nickel-catalyzed electrochemical reductive coupling of halides.
Scheme 68: Nickel-electrocatalyzed enantioselective carboxylation with CO2.
Scheme 69: Reductive electrophotocatalysis for borylation.
Scheme 70: Electromediated photoredox catalysis for selective C(sp3)–O cleavages of phosphinated alcohols to c...
Scheme 71: Stereoselective electro-2-deoxyglycosylation from glycals. MFE = methyl nonafluorobutyl ether.
Scheme 72: Electrochemical peptide modifications.
Scheme 73: Electrochemical α-deuteration of amides.
Scheme 74: Electrochemical synthesis of gem-diselenides.
Scheme 75: Site-selective electrochemical aromatic C–H amination.
Scheme 76: Electrochemical coupling of heteroarenes with heteroaryl phosphonium salts.
Scheme 77: Redox-neutral strategy for the dehydroxyarylation reaction.
Scheme 78: Nickel-catalyzed electrochemical C(sp3)–C(sp2) cross-coupling of benzyl trifluoroborate and halides....
Scheme 79: Paired electrocatalysis for C(sp3)–C(sp2) coupling.
Scheme 80: Redox-neutral strategy for amination of aryl bromides.
Scheme 81: Redox-neutral cross-coupling of aryl halides with weak N-nucleophiles. aProtocol with (+) RVC | RVC...
Scheme 82: Nickel-catalyzed N-arylation of NH-sulfoximines with aryl halides.
Scheme 83: Esterification of carboxylic acids with aryl halides.
Scheme 84: Electrochemically promoted nickel-catalyzed carbon–sulfur-bond formation. GFE = graphite felt elect...
Scheme 85: Electrochemical deoxygenative thiolation by Ni-catalysis. GFE = graphite felt electrode; NFE = nick...
Scheme 86: Electrochemical coupling of peptides with aryl halides.
Scheme 87: Paired electrolysis for the phosphorylation of aryl halides. GFE = graphite felt electrode, FNE = f...
Scheme 88: Redox-neutral alkoxyhalogenation of alkenes.
Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles
- Yutaro Miyashita,
- Sae Someya,
- Tomoko Kawasaki-Takasuka,
- Tomohiro Agou and
- Takashi Yamazaki
Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206
- executed at −78 °C under the action of LDA [29]. Moreover, by using the epoxyester 2b as the representative substrate, clarification of its reactivity was carried out by mixing with 1) heteronucleophiles like amines, thiols, and magnesium halides, 2) softer carbon nucleophiles such as malonates, and 3
Graphical Abstract
Scheme 1: Expectation of the regio- as well as stereoselective reactions of 2.
Scheme 2: Attempts of the present epoxidation to other α,β-unsaturated esters, 1h–j.
Figure 1: Crystallographic structure of the epoxy ring-opening products by PhCH(NH2)Me (3bd) and PhCH2SH (4ba...
Scheme 3: Introduction of additional halogen atoms at the 2-position of the compound 2b.
Scheme 4: Clarification of the stereochemistry of anti,syn-8a and -7b.
Figure 2: Crystallographic structure of anti,syn-8a.
Scheme 5: Reaction of 2b with other stabilized nucleophiles.
Scheme 6: Production of 4,4,4-trifluoro-2,3-dihydroxybutanoate anti-10a.
Scheme 7: Reactions of n-C10H21MgBr-based cuprate with 13f as well as 2b with/without D2O quenching.
Figure 3: A part of 13C NMR spectra for the compounds 11a and 11a-D.
Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO
- Hisanori Senboku and
- Mizuki Hayama
Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203
- competitively occurs at the cathode, and an excess amount of electricity should therefore be necessary to obtain acceptable results. At the anode, on the other hand, dissolution of magnesium ions by electrochemical oxidation of magnesium metal occurs, preventing electrochemical oxidation of the product and
- intermediates at the anode. The produced acetate ion D and a magnesium ion form the salt E, which upon acid treatment during workup gives a diphenylacetic acid 2. The effects of DMSO as solvent are not clear at present, and one reasonable and acceptable aspect might be the solubility of the salt of intermediate
- cation of intermediate B is thought to be the magnesium ion, and the magnesium salt of B must be dissolved in the solvent. Although other magnesium salts, such as magnesium carbonate and magnesium oxalate, are also generated during the electrolysis, the magnesium salt of B would be dissolved sufficiently
Graphical Abstract
Scheme 1: Synthesis of diarylacetic acids 2 from diarylmethanol compounds 1 and carbon dioxide.
Scheme 2: Attempted electrochemical carboxylation of halogen-containing diphenylmethanol compounds 1b and 1c.
Scheme 3: Synthesis of diarylacetic acids 2 by electrochemical carboxylation of diarylmethanol species 1.
Scheme 4: Attempted electrochemical carboxylation of 1m and 1n.
Scheme 5: Electrolysis of 1a under a nitrogen atmosphere.
Scheme 6: Plausible reaction pathways.
Cell-free protein synthesis with technical additives – expanding the parameter space of in vitro gene expression
- Tabea Bartsch,
- Stephan Lütz and
- Katrin Rosenthal
Beilstein J. Org. Chem. 2024, 20, 2242–2253, doi:10.3762/bjoc.20.192
- the magnesium and potassium glutamate concentration, is 140 mM, which is less than half the concentration reported for the cellular environment. The cytoplasmic osmolarity of about 600 mOsm [16] is 50% higher than that calculated for CFPS. Taking into account all defined components, the water content
- for the calculation of the macromolecular concentration of the CFPS mix. Magnesium and potassium glutamate were considered as the contributing inorganic ions for the reference composition, for the DES corresponding salts were added to the value of 140 mM. For the osmolarity the concentrations of all
- defined components were multiplied with their number of dissociated particles, which was assumed as 1 for most components and 2 for magnesium and potassium glutamate and combined with the calculated concentration of macromolecules. For the water content, the amount of all known components was subtracted
Graphical Abstract
Figure 1: CFPS of sfGFP with different technical additives at various concentrations. Experiments with 2% PEG...
Figure 2: CFPS of thscGAS-sfGFP with different technical additives at various concentrations. Experiments wit...
Electrochemical allylations in a deep eutectic solvent
- Sophia Taylor and
- Scott T. Handy
Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189
- (entry 1) resulted in good conversion to the allylation product, while zinc, magnesium, and graphite (Table 1, entries 3–5) displayed no reaction at all. This observation was somewhat surprising considering that both zinc and tin are very commonly used in conventional allylations in addition to as
- funnel with the aid of 10 mL of deionized (DI) water followed by 20 mL of diethyl ether. The organic layer was separated, dried with anhydrous magnesium sulfate, filtered, and the solvent removed in vacuo to afford the crude product, which was first analyzed by 1H NMR spectroscopy and then purified using
- potential conditions of 2 V with no reference electrode until 2.5 F/mol was passed. Following completion of each reaction, the mixture was transferred to a separatory funnel with the aid of 10 mL of DI water followed by 20 mL of diethyl ether. The organic layer was separated, dried with anhydrous magnesium
Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps
- Ignaz Betcke,
- Alissa C. Götzinger,
- Maryna M. Kornet and
- Thomas J. J. Müller
Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178
- [135]. Following this, a one-pot process involving Michael addition/cyclocondensation with hydrazine derivatives leads to the corresponding pyrazoles. Since magnesium ions are formed during the Kumada coupling, the additive phenanthroline must be added during the cyclization step to prevent the
- coordination of the magnesium ions and subsequent hydrazine inactivation. The diversity-oriented nature of this consecutive four-component synthesis was used to synthesize 17 different donor/acceptor-substituted pyrazoles 108 in moderate to good yields (Scheme 39) [136]. The synthesis of bispyrazoles was also
Graphical Abstract
Scheme 1: Consecutive three-component synthesis of pyrazoles 1 via in situ-formed 1,3-diketones 2 [44].
Scheme 2: Consecutive three-component synthesis of 4-ethoxycarbonylpyrazoles 5 via SmCl3-catalyzed acylation ...
Scheme 3: Consecutive four-component synthesis of 1-(thiazol-2-yl)pyrazole-3-carboxylates 8 [51].
Scheme 4: Three-component synthesis of thiazolylpyrazoles 17 via in situ formation of acetoacetylcoumarins 18 ...
Scheme 5: Consecutive pseudo-four-component and four-component synthesis of pyrazoles 21 from sodium acetylac...
Scheme 6: Consecutive three-component synthesis of 1-substituted pyrazoles 24 from boronic acids, di(Boc)diim...
Scheme 7: Consecutive three-component synthesis of N-arylpyrazoles 25 via in situ formation of aryl-di(Boc)hy...
Scheme 8: Consecutive three-component synthesis of 1,3,4-substituted pyrazoles 27 and 28 from methylhydrazine...
Scheme 9: Consecutive three-component synthesis of 4-allylpyrazoles 32 via oxidative allylation of 1,3-dicarb...
Scheme 10: Pseudo-five-component synthesis of tris(pyrazolyl)methanes 35 [61].
Scheme 11: Pseudo-three-component synthesis of 5-(indol-3-yl)pyrazoles 39 from 1,3,5-triketones 38 [64].
Scheme 12: Three-component synthesis of thiazolylpyrazoles 43 [65].
Scheme 13: Three-component synthesis of triazolo[3,4-b]-1,3,4-thiadiazin-3-yl substituted 5-aminopyrazoles 47 [67]....
Scheme 14: Consecutive three-component synthesis of 5-aminopyrazoles 49 via formation of β-oxothioamides 50 [68].
Scheme 15: Synthesis of 3,4-biarylpyrazoles 52 from aryl halides, α-bromocinnamaldehyde, and tosylhydrazine vi...
Scheme 16: Consecutive three-component synthesis of 3,4-substituted pyrazoles 57 from iodochromones 55 by Suzu...
Scheme 17: Pseudo-four-component synthesis of pyrazolyl-2-pyrazolines 59 by ring opening/ring closing cyclocon...
Scheme 18: Consecutive three-component synthesis of pyrazoles 61 [77].
Scheme 19: Three-component synthesis of pyrazoles 62 from malononitrile, aldehydes, and hydrazines [78-90].
Scheme 20: Four-component synthesis of pyrano[2,3-c]pyrazoles 63 [91].
Scheme 21: Three-component synthesis of persubstituted pyrazoles 65 from aldehydes, β-ketoesters, and hydrazin...
Scheme 22: Three-component synthesis of pyrazol-4-carbodithioates 67 [100].
Scheme 23: Regioselective three-component synthesis of persubstituted pyrazoles 68 catalyzed by ionic liquid [...
Scheme 24: Consecutive three-component synthesis of 4-halopyrazoles 69 and anellated pyrazoles 70 [102].
Scheme 25: Three-component synthesis of 2,2,2-trifluoroethyl pyrazole-5-carboxylates 72 [103].
Scheme 26: Synthesis of pyrazoles 75 in a one-pot process via carbonylative Heck coupling and subsequent cycli...
Scheme 27: Copper-catalyzed three-component synthesis of 1,3-substituted pyrazoles 76 [105].
Scheme 28: Pseudo-three-component synthesis of bis(pyrazolyl)methanes 78 by ring opening-ring closing cyclocon...
Scheme 29: Three-component synthesis of 1,4,5-substituted pyrazoles 80 [107].
Scheme 30: Consecutive three-component synthesis of 3,5-bis(fluoroalkyl)pyrazoles 83 [111].
Scheme 31: Consecutive three-component synthesis of difluoromethanesulfonyl-functionalized pyrazole 88 [114].
Scheme 32: Consecutive three-component synthesis of perfluoroalkyl-substituted fluoropyrazoles 91 [115].
Scheme 33: Regioselective consecutive three-component synthesis of 1,3,5-substituted pyrazoles 93 [116].
Scheme 34: Three-component synthesis of pyrazoles 96 mediated by trimethyl phosphite [117].
Scheme 35: One-pot synthesis of pyrazoles 99 via Liebeskind–Srogl cross-coupling/cyclocondensation [118].
Scheme 36: Synthesis of 1,3,5-substituted pyrazoles 101 via domino condensation/Suzuki–Miyaura cross-coupling ...
Scheme 37: Consecutive three-component synthesis of 1,3,5-trisubstituted pyrazoles 102 and 103 by Sonogashira ...
Scheme 38: Polymer analogous consecutive three-component synthesis of pyrazole-based polymers 107 [132].
Scheme 39: Synthesis of 1,3,5-substituted pyrazoles 108 by sequentially Pd-catalyzed Kumada–Sonogashira cycloc...
Scheme 40: Consecutive four-step one-pot synthesis of 1,3,4,5-substituted pyrazoles 110 [137].
Scheme 41: Four-component synthesis of pyrazoles 113, 115, and 117 via Sonogashira coupling and subsequent Suz...
Scheme 42: Consecutive four- or five-component synthesis for the preparation of 4-pyrazoly-1,2,3-triazoles 119...
Scheme 43: Four-component synthesis of pyrazoles 121 via alkynone formation by carbonylative Pd-catalyzed coup...
Scheme 44: Preparation of 3-azulenyl pyrazoles 124 by glyoxylation, decarbonylative Sonogashira coupling, and ...
Scheme 45: Four-component synthesis of a 3-indoloylpyrazole 128 [147].
Scheme 46: Two-step synthesis of 5-acylpyrazoles 132 via glyoxylation-Stephen–Castro sequence and subsequent c...
Scheme 47: Copper on iron mediated consecutive three-component synthesis of 3,5-substituted pyrazoles 136 [150].
Scheme 48: Consecutive three-component synthesis of 3-substituted pyrazoles 141 by Sonogashira coupling and su...
Scheme 49: Consecutive three-component synthesis of pyrazoles 143 initiated by Cu(I)-catalyzed carboxylation o...
Scheme 50: Consecutive three-component synthesis of benzamide-substituted pyrazoles 146 starting from N-phthal...
Scheme 51: Consecutive three-component synthesis of 1,3,5-substituted pyrazoles 148 [156].
Scheme 52: Three-component synthesis of 4-ninhydrin-substituted pyrazoles 151 [158].
Scheme 53: Consecutive four-component synthesis of 4-(oxoindol)-1-phenylpyrazole-3-carboxylates 155 [159].
Scheme 54: Three-component synthesis of pyrazoles 160 [160].
Scheme 55: Consecutive three-component synthesis of pyrazoles 165 [162].
Scheme 56: Consecutive three-component synthesis of 3,5-disubstituted and 3-substituted pyrazoles 168 and 169 ...
Scheme 57: Three-component synthesis of 3,4,5-substituted pyrazoles 171 via 1,3-dipolar cycloaddition of vinyl...
Scheme 58: Three-component synthesis of pyrazoles 173 and 174 from aldehydes, tosylhydrazine, and vinylidene c...
Scheme 59: Three-component synthesis of pyrazoles 175 from glyoxyl hydrates, tosylhydrazine, and electron-defi...
Scheme 60: Pseudo-four-component synthesis of pyrazoles 177 from glyoxyl hydrates, tosylhydrazine, and aldehyd...
Scheme 61: Consecutive three-component synthesis of pyrazoles 179 via Knoevenagel-cycloaddition sequence [179].
Scheme 62: Three-component synthesis of 5-dimethylphosphonate substituted pyrazoles 182 from aldehydes, the Be...
Scheme 63: Consecutive three-component synthesis of 5-(dimethyl phosphonate)-substituted pyrazoles 185 from al...
Scheme 64: Three-component synthesis of 5-(dimethyl phosphonate)-substituted pyrazoles 187 from aldehydes, the...
Scheme 65: Three-component synthesis of 5-diethylphosphonate/5-phenylsulfonyl substituted pyrazoles 189 from a...
Scheme 66: Pseudo-three-component synthesis of 3-(dimethyl phosphonate)-substituted pyrazoles 190 [185].
Scheme 67: Three-component synthesis of 3-trifluoromethylpyrazoles 193 [186].
Scheme 68: Consecutive three-component synthesis of 5-stannyl-substituted 4-fluoropyrazole 197 [191,192].
Scheme 69: Pseudo-three-component synthesis of 3,5-diacyl-4-arylpyrazoles 199 [195].
Scheme 70: Three-component synthesis of pyrazoles 204 via nitrilimines [196].
Scheme 71: Three-component synthesis of 1,3,5-substituted pyrazoles 206 via formation of nitrilimines and sali...
Scheme 72: Pseudo four-component synthesis of pyrazoles 209 from acetylene dicarboxylates 147, hydrazonyl chlo...
Scheme 73: Consecutive three-component synthesis of pyrazoles 213 via syndnones 214 [200].
Scheme 74: Consecutive three-component synthesis of pyrazoles 216 via in situ-formed diazomethinimines 217 [201].
Scheme 75: Consecutive three-component synthesis of 3-methylthiopyrazoles 219 from aldehydes, hydrazine, and 1...
Scheme 76: Three-component synthesis of 1,3,5-substituted pyrazoles 220 from aldehydes, hydrazines, and termin...
Scheme 77: Three-component synthesis of 1,3,4,5-substituted pyrazoles 222 from aldehydes, hydrazines, and DMAD ...
Scheme 78: Pseudo three-component synthesis of pyrazoles 224 from sulfonyl hydrazone and benzyl acrylate under...
Scheme 79: Titanium-catalyzed consecutive four-component synthesis of pyrazoles 225 via enamino imines 226 [211]. a...
Scheme 80: Titanium-catalyzed three-component synthesis of pyrazoles 227 via enhydrazino imine complex interme...
Scheme 81: Pseudo-three-component synthesis of pyrazoles 229 via Glaser coupling of terminal alkynes and photo...
Scheme 82: Copper(II)acetate-mediated three-component synthesis of pyrazoles 232 [216].
Scheme 83: Copper-catalyzed three-component synthesis of 1,3,4-substituted pyrazole 234 from oxime acetates, a...
Scheme 84: Three-component synthesis of 3-trifluoroethylpyrazoles 239 [218].
Scheme 85: Pseudo-three-component synthesis of 1,4-bisulfonyl-substituted pyrazoles 242 [219].
Scheme 86: Three-component synthesis of 4-hydroxypyrazole 246 [221].
1,2-Difluoroethylene (HFO-1132): synthesis and chemistry
- Liubov V. Sokolenko,
- Taras M. Sokolenko and
- Yurii L. Yagupolskii
Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171
- magnesium [50][51] to form the desired 1,2-difluoroethylene as a mixture of E- and Z-isomers, which were separated by fractional distillation (boiling point: −53.1 °C for (E)-HFO-1132 and −26.0 °C for (Z)-HFO-1132 [47]). In patent literature, a variety of synthetic routes to HFO-1132 starting from other
Graphical Abstract
Scheme 1: 1,2-Difluoroethylene synthesis from HFO-1123.
Scheme 2: 1,2-Difluoroethylene synthesis from CFC-112 and HCFC-132.
Scheme 3: 1,2-Difluoroethylene synthesis from HFC-143.
Scheme 4: 1,2-Difluoroethylene synthesis from HCFC-142 via HCFC-142a.
Scheme 5: 1,2-Difluoroethylene synthesis from CFO-1112.
Scheme 6: 1,2-Difluoroethylene synthesis from 1,2-dichloroethylene.
Scheme 7: 1,2-Difluoroethylene synthesis from perfluoropropyl vinyl ether.
Scheme 8: Deuteration reaction of 1,2-difluoroethylene.
Scheme 9: Halogen addition to 1,2-difluoroethylene.
Scheme 10: Hypohalite addition to 1,2-difluoroethylene.
Scheme 11: N-Bromobis(trifluoromethyl)amine addition to 1,2-difluoroethylene.
Scheme 12: N-Chloroimidobis(sulfonyl fluoride) addition to 1,2-difluoroethylene.
Scheme 13: Trichlorosilane addition to 1,2-difluoroethylene.
Scheme 14: SF5Br addition to 1,2-difluoroethylene.
Scheme 15: PCl3/O2 addition to 1,2-difluoroethylene.
Scheme 16: Reaction of tetramethyldiarsine with 1,2-difluoroethylene.
Scheme 17: Reaction of trichlorofluoromethane with 1,2-difluoroethylene.
Scheme 18: Addition of perfluoroalkyl iodides to 1,2-difluoroethylene.
Scheme 19: Cyclopropanation of 1,2-difluoroethylene.
Scheme 20: Diels–Alder reaction of 1,2-difluoroethylene and hexachlorocyclopentadiene.
Scheme 21: Cycloaddition reaction of 1,2-difluoroethylene and fluorinated ketones.
Scheme 22: Cycloaddition reaction of 1,2-difluoroethylene and perfluorinated aldehydes.
Scheme 23: Photochemical cycloaddition of 1,2-difluoroethylene and hexafluorodiacetyl.
Scheme 24: Reaction of 1,2-difluoroethylene with difluorosilylene.
Scheme 25: Reaction of 1,2-difluoroethylene with aryl iodides.
Synthetic applications of the Cannizzaro reaction
- Bhaskar Chatterjee,
- Dhananjoy Mondal and
- Smritilekha Bera
Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120
- proceeded with modest to good yields, in the range of 40–82%, and depicts the Cannizzaro reaction in the transfer hydrogenation process [35]. A facile room temperature Cannizzaro reaction protocol was established by Abaee et al. employing magnesium bromide etherate and triethylamine in dichloromethane [77
Graphical Abstract
Figure 1: Types and mechanism of the Cannizzaro reaction.
Figure 2: Various approaches of the Cannizzaro reaction.
Figure 3: Representative molecules synthesized via the Cannizzaro reaction.
Scheme 1: Intramolecular Cannizzaro reaction of aryl glyoxal hydrates using TOX catalysts.
Scheme 2: Intramolecular Cannizzaro reaction of aryl methyl ketones using ytterbium triflate/selenium dioxide....
Scheme 3: Intramolecular Cannizzaro reaction of aryl glyoxals using Cr(ClO4)3 as catalyst.
Scheme 4: Cu(II)-PhBox-catalyzed asymmetric Cannizzaro reaction.
Scheme 5: FeCl3-based chiral catalyst applied for the enantioselective intramolecular Cannizzaro reaction rep...
Scheme 6: Copper bis-oxazoline-catalysed intramolecular Cannizzaro reaction and proposed mechanism.
Scheme 7: Chiral Fe catalysts-mediated enantioselective Cannizzaro reaction.
Scheme 8: Ruthenium-catalyzed Cannizzaro reaction of aromatic aldehydes.
Scheme 9: MgBr2·Et2O-assisted Cannizzaro reaction of aldehydes.
Scheme 10: LiBr-catalyzed intermolecular Cannizzaro reaction of aldehydes.
Scheme 11: γ-Alumina as a catalyst in the Cannizzaro reaction.
Scheme 12: AlCl3-mediated Cannizzaro disproportionation of aldehydes.
Scheme 13: Ru–N-heterocyclic carbene catalyzed dehydrogenative synthesis of carboxylic acids.
Figure 4: Proposed catalytic cycle for the dehydrogenation of alcohols.
Scheme 14: Intramolecular desymmetrization of tetraethylene glycol.
Scheme 15: Desymmetrization of oligoethylene glycol dialdehydes.
Scheme 16: Intramolecular Cannizzaro reaction of calix[4]arene dialdehydes.
Scheme 17: Desymmetrization of dialdehydes of symmetrical crown ethers using Ba(OH)2.
Scheme 18: Synthesis of ottelione A (proposed) via intramolecular Cannizzaro reaction.
Scheme 19: Intramolecular Cannizzaro reaction for the synthesis of pestalalactone.
Scheme 20: Synthetic strategy towards nigricanin involving an intramolecular Cannizzaro reaction.
Scheme 21: Spiro-β-lactone-γ-lactam part of oxazolomycins via aldol crossed-Cannizzaro reaction.
Scheme 22: Synthesis of indole alkaloids via aldol crossed-Cannizzaro reaction.
Scheme 23: Aldol and crossed-Cannizzaro reaction towards the synthesis of ertuliflozin.
Scheme 24: Synthesis of cyclooctadieneones using a Cannizzaro reaction.
Scheme 25: Microwave-assisted crossed-Cannizzaro reaction for the synthesis of 3,3-disubstituted oxindoles.
Scheme 26: Synthesis of porphyrin-based rings using the Cannizzaro reaction.
Scheme 27: Synthesis of phthalides and pestalalactone via Cannizarro–Tishchenko-type reaction.
Scheme 28: Synthesis of dibenzoheptalene bislactones via a double intramolecular Cannizzaro reaction.
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
Graphical Abstract
Figure 1: Biosynthetic pathway of terpenoids. Valuable terpenoids, noncanonical C11 and C16 terpenes are show...
Figure 2: Representative terpenoids produced by plant MSTSs. a) 6 and 7 are products of PamTps1 from Plectran...
Figure 3: The structure of representative terpene products of MSTSs. a) From fungi: compounds 30–33 are produ...
Figure 4: Terpenoid products of TSs using chemically synthesized noncanonical prenyl substrates. a) Products ...
Figure 5: Biotransformation of noncanonical prenyl analogs 60–65 using two terpene synthases, limonene syntha...
Figure 6: Noncanonical substrates for mechanism studies and their conversion to new terpenoids. a) New terpen...
Figure 7: A series of prenyl diphosphate building blocks produced by different IPP methyltransferases. humMT ...
Figure 8: The structure of noncanonical prenyl substrates generated by C-methyltransferases and variants. a) ...
Figure 9: Structures of C16 terpenes identified via genome mining of C16 biosynthetic gene clusters from bact...
Figure 10: a) Precursors and final products of the MVA pathway and LMVA pathway. b) The structure of C6- and C7...
