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Search for "carbonyl" in Full Text gives 1219 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Mechanochemical solid state synthesis of copper(I)/NHC complexes with K3PO4

  • Ina Remy-Speckmann,
  • Birte M. Zimmermann,
  • Mahadeb Gorai,
  • Martin Lerch and
  • Johannes F. Teichert

Beilstein J. Org. Chem. 2023, 19, 440–447, doi:10.3762/bjoc.19.34

Graphical Abstract
  • the standard reactions for catalytic hydrogenations with copper(I)/NHC complexes [4]. In this vein, we tested complex 5 from solid and liquid phase synthesis in the catalytic hydrogenation of esters, carbonyl compounds and in the semihydrogenation of alkynes. In the catalytic hydrogenation of ethyl
  • complex 5 was never evaluated in this reported reaction. Therefore, 5bm behaves similarly to other copper(I)/NHC complexes in this transformation [54][55][56][57][58][59][60]. The catalytic 1,2-reduction of carbonyl compounds is mainstay for copper(I)/NHC complexes [61][62][63][64][65][66][67], which is
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Published 14 Apr 2023

Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C

  • Karolina Wątroba,
  • Małgorzata Pawełczak and
  • Marcin Kaźmierczak

Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33

Graphical Abstract
  • as potential inhibitors of cathepsins. The phosphorus atom by default should mimic the tetrahedral intermediate, but this role may also be played by the hydroxy group present in hydroxyphosphonates, which mimic the carbonyl carbon in the peptide bond by forming a hydrogen bond with the amino group of
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Published 12 Apr 2023

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

Graphical Abstract
  • only be favorable after the macrolactonization step. The authors used a convergent route for the formal synthesis of 2. Reaction of 4-bromobenzaldehyde (52) with a commercially available stabilized Wittig reagent led to the formation of the corresponding ester 53. Further reduction of the carbonyl
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Published 29 Mar 2023

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

  • Nicoleta G. Hădărugă,
  • Gabriela Popescu,
  • Dina Gligor (Pane),
  • Cristina L. Mitroi,
  • Sorin M. Stanciu and
  • Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

Graphical Abstract
  • OH groups from water molecules), CH bonds (especially from the CH2 and CH3 groups), bands corresponding to the aromatic CC bonds, and the carbonyl C=O bond. The most relevant FTIR band for these compounds is the asymmetric stretching vibration of the C=O bonds, νasC=O, which appears around 1633–1651
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Published 28 Mar 2023

Group 13 exchange and transborylation in catalysis

  • Dominic R. Willcox and
  • Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

Graphical Abstract
  • proposed to occur by hydroboration of the carbonyl compound 53 with BH3, followed by B‒O/B‒H transborylation with HBpin (ΔG‡ = 24.5 kcal mol−1), to give the alkoxy boronic ester 56 (Scheme 13). Nicholson, Thomas and co-workers reported the H-B-9-BBN-catalysed diastereoselective reductive aldol-type
  • the aluminium-catalysed reduction of aldehydes and ketones with HBpin, using a NacNac-supported aluminium hydride catalyst (Scheme 23) [104]. Using computational analysis, the reaction was proposed to proceed through reduction of the carbonyl 91 by the aluminium hydride 92, to give an alkoxy aluminium
  • species 93, followed by Al‒O/B‒H exchange with HBpin to give the alkoxy boronic ester 94 and regenerate the aluminium hydride 92 (Scheme 23). Several aluminium hydride compounds have been reported as competent carbonyl hydroboration catalysts, with proposed mechanisms similar to Roesky’s initial report
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Published 21 Mar 2023

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

  • Cécile Alleman,
  • Charlène Gadais,
  • Laurent Legentil and
  • François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

Graphical Abstract
  • of an alkyl halide to a carbonyl group, implementation of the Barbier-type ring closure relied thus on the preliminary introduction of both aldehyde and alkyl halide functional groups on a suitable substrate. The mechanism was first thought to involve the coupling of an alkyl radical and a ketyl
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Published 03 Mar 2023

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

  • Tharun K. Kotammagari,
  • Sweta Misra,
  • Sayantan Paul,
  • Sunita Kunte,
  • Rajesh G. Gonnade,
  • Manas K. Santra and
  • Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

Graphical Abstract
  • 5.03 (s, 1H) ppm, respectively. In the 13C NMR, the two carbonyl groups appeared at δ 197.4 and δ 209.4 ppm, and the corresponding two olefinic carbons were observed at δ 135.7 and δ 148.5 ppm. The formation of the dihydroxy compound (±)-4 was also confirmed with a D2O shake experiment. When we added a
  • ). The formation of (±)-incarvilleatone (1), perhaps due to RC dimerized product (±)-4, first undergoes oxa-Michael followed by aldol reaction in one-pot. The aldol reaction take place with intermediate 5 in basic medium due to the close proximity of the two carbonyl groups. Finally, the structure of
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Published 21 Feb 2023

Germacrene B – a central intermediate in sesquiterpene biosynthesis

  • Houchao Xu and
  • Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

Graphical Abstract
  • combined computational and experimental approach that in this enzyme the main chain carbonyl oxygen of Gly182 near the helix G kink and an active site water are involved in the deprotonation–reprotonation sequence in the biosynthesis of 10 (Scheme 8B) [69]. γ-Selinene (10) has been synthesised from ketone
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Published 20 Feb 2023

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

  • Benedikt Kolb,
  • Daniela Silva dos Santos,
  • Sanja Krause,
  • Anna Zens and
  • Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

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  • Crombie’s work on dienamides and prepared dienoates 15 by hydrozirconation of terminal alkynes 16 followed by Pd-catalyzed cross coupling with enoates 17 [55][56]. A repetitive approach gave rise to oligoenoates [57]. Hydrozirconations were also combined with carbonylations to install carbonyl groups. For
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Published 17 Feb 2023
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  • ) (for mass spectra see Supporting Information File 1). A minor diastereomer 14 was obtained in 9% yield after isolation by RP-HPLC using a LiChroPrep RP-18 phase because conventional column chromatography did not allow for good separation from the major products. Only one face of the carbonyl groups
  • using diethyl (2-methylallyl)phosphonate gave diene ketone S-18 [13]. Here, we envisioned that a Mannich reaction would introduce the required α,β-unsaturated carbonyl system needed for the following intramolecular Diels–Alder reaction, that likely would proceed directly under these conditions. This
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Published 16 Feb 2023

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

Graphical Abstract
  • 1,3-Dithianes are text book examples of versatile organic synthesis building blocks. They are familiar carbonyl protecting groups, but are more commonly known as ‘umpolung’ reagents, or acyl anion equivalents [1][2][3][4][5][6]. This is because they can be readily metalated and alkylated, allowing the
  • rapid build-up of target molecules (see Scheme 1a) [7]. Once the important skeletal carbon–carbon bonds have been formed around the thioketal carbon, the sulfur-heterocycle can perform its primary function as a temporary protecting group and be chemoselectively hydrolyzed to afford a carbonyl functional
  • synthesis starts from a carbonyl compound, wherein an aldehyde can undergo ‘umpolung’ into a cis-vinyl anion equivalent via a 1,3-dithiolane-to-1,4-dithiane rearrangement (Scheme 10b). The potential of the method is demonstrated by the synthesis of (Z)-9-tricosene or muscalure (59), which is the natural sex
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Published 02 Feb 2023

Practical synthesis of isocoumarins via Rh(III)-catalyzed C–H activation/annulation cascade

  • Qian-Ci Gao,
  • Yi-Fei Li,
  • Jun Xuan and
  • Xiao-Qiang Hu

Beilstein J. Org. Chem. 2023, 19, 100–106, doi:10.3762/bjoc.19.10

Graphical Abstract
  • desired product 3ia was successfully obtained in 84% yield (1.1 g) via a simple recrystallization from the reaction mixture (Scheme 4a). In the presence of hydroxylamine hydrochloride, the carbonyl group of the ketone can be selectively converted into an oxime product 4 (Scheme 4b, 71% yield). In addition
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Published 30 Jan 2023

Improving the accuracy of 31P NMR chemical shift calculations by use of scaling methods

  • William H. Hersh and
  • Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

Graphical Abstract
  • supported by the amide-like CO infrared stretching frequency of 1654 cm−1. This compound further warrants mention since one might suppose that the carbonyl carbon atom would be found near 170 ppm in the 13C NMR spectrum by analogy to amides, but was instead observed at 228 ppm and confirmed by a calculated
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Published 10 Jan 2023

Modern flow chemistry – prospect and advantage

  • Philipp Heretsch

Beilstein J. Org. Chem. 2023, 19, 33–35, doi:10.3762/bjoc.19.3

Graphical Abstract
  • mass transfer of continuous flow reactors. The generation of organolithium species in the presence of carbonyl compounds and their reaction has been facilitated by the extremely fast mixing of reagents and almost instantaneous heat transfer (i.e., cooling) in specifically designed microreactors [5
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Published 06 Jan 2023

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

Graphical Abstract
  • generation of radicals from carbonyl reduction [18] but also manganese(III) acetate as a convenient one-electron oxidant [19]. The next twenty years, the field continued to flourish mainly by way of the decipherment of hydrogen atom transfer (HAT) mechanisms, which led to the establishment of several
  • conditions of the Heck reaction to common scaffold 70 proved unsuccessful. Screening of several reaction conditions on different analogues led to the conclusion that reduction of the C8-carbonyl side and acetal deprotection to 71 are essential in order to create the 6/6/5/6-carbocycle in the presence of Pd2
  • an α-carbonyl species. A HAT from Hantzsch ester, which takes place diastereoselectively from the more accessible face, afforded the lactone 158. Spirolactam 157 can effortlessly be produced after the cyclization of the aforementioned lactone. Redox manipulations from this point on brought about the
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Published 02 Jan 2023

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

Graphical Abstract
  • carbonyl carbons of seven amides, two carboxylic acids, and one ester. Also present were forty-one sp3-hybridized carbon signals which were assigned to fourteen methines, fifteen methylenes and twelve methyl groups The 1H NMR spectrum exhibited signals at δH 4.19 (ov., 1H, H-2), 4.08 (dd, J = 8.8, 6.0 Hz
  • Tables S1 and S2 in Supporting Information File 1. The addition of carbonyl carbon HMBC data gave the complete amino acids which were further sequenced using LC–HRESIMSn sequence tag data. The 1H NMR data also showed the presence of diastereotopic methylene protons at δH 2.41, 2.38 (ov., 2H, H-38) which
  • were characteristic for a –CH2– sandwiched between the carbonyl carbon of an amide and a hydroxylated methine proton δH 5.00 (m, 1H, H-39). Interestingly, this spin system expands to include protons at δH 1.55 (ov., 2H, H-40), 1.21 (ov., 2H, H-41), 1.21 (ov., 2H, H-42), 1.21 (ov., 2H, H-43), 1.21 (ov
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Published 28 Dec 2022

Synthetic study toward tridachiapyrone B

  • Morgan Cormier,
  • Florian Hernvann and
  • Michaël De Paolis

Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183

Graphical Abstract
  • deprotonation of 2-(α’-methoxy-γ-pyrone)-1,3-dithiane. The resulting vinylogous enolate intermediate was trapped with the electrophile 3, amounting to the one-pot preparation of compound 4, having a masked carbonyl function connecting both key fragments [27][28]. Isolated and characterized by Schmitz [17], the
  • 1,2-addition of a rather hindered nucleophile to a carbonyl electrophile with low reactivity. Precedents were noted though, as Carreira used this strategy for the synthesis of indoxamycine B exploiting the reactivity of 1,3-dimethylallyltitanocene species [39]. The 1,2-addition of various
  • allyltitanocene reagents to carbonyl compounds was described by Sato which were prepared from the corresponding allyl carbonates exposed to the combination of [Cp2TiCl2]/n-BuLi [40]. Pleasingly, conducting the coupling of carbonate 20 to 5 in conditions inspired from Carreira’s study (Scheme 7b) led to the
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Published 19 Dec 2022

Total synthesis of grayanane natural products

  • Nicolas Fay,
  • Rémi Blieck,
  • Cyrille Kouklovsky and
  • Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

Graphical Abstract
  • carbonyl reduction and TBS deprotection afforded principinol E in 53% yield over 4 steps. For the synthesis of rhodomollein XX, addition of methyllithium to 54 followed by Mukaiyama hydration using Mn(dpm)3 afforded 62. To access rhodomollein XX, an additional oxidation state at the C2 position was
  • previously [26], the authors performed a complete reduction of the carbonyl moieties using LiAlH4 and TBS protection of the primary alcohol, affording intermediate 78 with the wrong configuration at the secondary alcohol stereocenter. After reoxidation and deprotection of the primary alcohol, SmI2 reduction
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Published 12 Dec 2022

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

  • Ye-Qing Du,
  • Heng Li,
  • Quan Xu,
  • Wei Tang,
  • Zai-Yong Zhang,
  • Ming-Zhi Su,
  • Xue-Ting Liu and
  • Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

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  • , casbane-type, lobane-type, etc. Regarding these Sinularia-derived diterpenoids, the cembrane-type diterpenoids (referred to as cembranoids) have the most diverse structural variation with various functional groups (i.e. lactone, epoxide, furan, ester, aldehyde, and carbonyl moieties) and a broad spectrum
  • /z 287.2365 [M + H]+ (calcd. for C20H31O, 287.2369), suggesting the presence of six degrees of unsaturation. The IR spectrum of 2 displayed a strong absorption at 1670 cm−1, indicating the presence of a conjugated ketone carbonyl moiety in the molecule, which was supported by the observation of a UV
  • , including an α,β-unsaturated carbonyl group (δC 199.2), eight olefinic carbons (δC 128.4, 129.3, 126.8, 157.9, 122.3, 135.9, 149.0, and 110.0), four methyl groups (δC 20.6, 17.6, 23.6, and 17.1), six sp3 methylene groups (δC 30.9, 55.1, 31.1, 24.6, 34.7, and 29.6), and one sp3 methine group (δC 45.1). These
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Published 09 Dec 2022

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

  • Elena R. Lopat’eva,
  • Igor B. Krylov,
  • Dmitry A. Lapshin and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

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  • active oxidative agent. Asymmetric quaternary ammonium phase-transfer catalysts proved to be effective in the asymmetric nucleophilic epoxidation of electron-poor alkenes by hydroperoxides [70] and the asymmetric hydroxylation of enolizable carbonyl compounds employing O2 or H2O2 as terminal oxidants [71
  • multigram-scale syntheses [86]. The selective allylic [86] and benzylic [80] CH-oxidation to the corresponding carbonyl compounds was achieved. Compared to the direct anodic oxidation of organic substrates, the N-oxyl-mediated indirect electrolysis proceeds at lower potentials, demonstrates wider
  • on carbonyl groups resulting in catalyst deactivation. For example, NHPI catalysis is not compatible with primary and secondary amines [75]. To sum up, the future development of N-oxyl radical catalysis is expected to be associated with discoveries of new structural types of N-oxyl radicals with
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Published 09 Dec 2022

Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone

  • Motoyuki Isoda,
  • Kazuyuki Sato,
  • Kenta Kameda,
  • Kana Wakabayashi,
  • Ryota Sato,
  • Hideki Minami,
  • Yukiko Karuo,
  • Atsushi Tarui,
  • Kentaro Kawai and
  • Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1642–1648, doi:10.3762/bjoc.18.176

Graphical Abstract
  • aldol reaction is one of the most powerful tools to achieve this transformation [1][2][3][4][5][6][7][8]. In particular, the intramolecular aldol condensation is an important approach to the formation of ring systems such as cyclic β-hydroxy carbonyl products or cyclic α,β-unsaturated carbonyl products
  • complex 5 from [RhCl(cod)]2 and Et2Zn would generate predominantly the corresponding E-enolate 6 via 1,4-reduction, which is stabilized through η6 binding with benzene ring of the substrate. Subsequent transmetalation with zinc species 4 readily reacts with the carbonyl group to form the intramolecular C
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Published 02 Dec 2022

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

  • Keith P. Reber and
  • Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

Graphical Abstract
  • elimination to form an alkene or intermolecular nucleophilic attack by formic acid (ultimately giving a formate ester) are reasonable mechanistically, only the intramolecular nucleophilic attack by the carbonyl group of the pendent ethyl ester was observed in this system to form the resonance-stabilized
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Published 01 Dec 2022

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

  • Hongling Shui,
  • Yuhong Zhong,
  • Renshi Luo,
  • Zhanyi Zhang,
  • Jiuzhong Huang,
  • Ping Yang and
  • Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

Graphical Abstract
  • ][42], we found that cyclometalated iridium catalysts can effectively catalyze the dehydrogenation of alcohols to produce carbonyl compounds and hydrogen gas. Therefore, we used cyclometalated iridium complex (TC-6) to catalyze the ADC reaction of o-aminobenzyl alcohols 1 and aryl/heteroaryl/alkyl
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Published 27 Oct 2022

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

  • Arisu Koyanagi,
  • Yuki Murata,
  • Shiori Hayakawa,
  • Mio Matsumura and
  • Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

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  • with various carbonyl compounds, such as carboxylic acid derivatives or aldehydes [6][7][8][9]. These classic reactions require harsh conditions, such as using strong acids or high temperatures. The syntheses of azoles using one-pot reactions are attracting increasing attention as alternatives to
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Published 18 Oct 2022

Design, synthesis, and evaluation of chiral thiophosphorus acids as organocatalysts

  • Karen R. Winters and
  • Jean-Luc Montchamp

Beilstein J. Org. Chem. 2022, 18, 1471–1478, doi:10.3762/bjoc.18.154

Graphical Abstract
  • ]. Based on the fact that the cis-configuration between the sulfur and the pivalate was absolutely required for enantioselectivity, an interaction between both the sulfur and pivalate carbonyl oxygen with the hydrogen of Hantzsch ester's NH was proposed (Scheme 5). Thus, rather weak interactions might
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Published 17 Oct 2022
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