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Search for "tert-butyl" in Full Text gives 682 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

  • Cristina Martini,
  • Muhammad Idham Darussalam Mardjan and
  • Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

Graphical Abstract
  • earth (RE) triflates before the report by Longo et al. [5], who found La and Gd performing better than Eu and Yb, and similarly to Sc in a model reaction between 2-aminopyridine (1), benzaldehyde (2) and tert-butyl isocyanide to give 3 under microwave (MW) heating. However, when methyl isocyanoacetate
  • replaced tert-butyl isocyanide, Gd(OTf)3 was superior to La(OTf)3, and again performed similarly to Sc(OTf)3 (Scheme 2). With these results in hand, Longo et al. evaluated the scope and limitations of this lanthanide, obtaining good to excellent results in the synthesis of 23 different GBB adducts, using
  • the addition of tert-butyl isocyanide. On the other hand, the addition of tert-butyl isocyanide on the imine altered the orientation of adduct 19, suppressing the interaction with Ser105 (Scheme 8). Very recently, Tyagi et al. reported the double encapsulation of CALB and Pd(PPh3)4 within silica
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Published 01 Aug 2024

Chiral bifunctional sulfide-catalyzed enantioselective bromolactonizations of α- and β-substituted 5-hexenoic acids

  • Sao Sumida,
  • Ken Okuno,
  • Taiki Mori,
  • Yasuaki Furuya and
  • Seiji Shirakawa

Beilstein J. Org. Chem. 2024, 20, 1794–1799, doi:10.3762/bjoc.20.158

Graphical Abstract
  • , respectively). These findings led us to further optimize the hydroxy-type chiral sulfide catalysts of type (S)-1. Substituting an alkyl group on sulfur of catalyst (S)-1 with isobutyl and tert-butyl [(S)-1b and 1c, respectively] decreased enantioselectivity compared with the n-butyl group-substituted catalyst
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Published 30 Jul 2024

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

  • Maria-Paula Schröder,
  • Isabel P.-M. Pfeiffer and
  • Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

Graphical Abstract
  • efficiency. PoyB was proposed to produce the N-terminal tert-butyl group of the polytheonamide A (Figure 4), but later PoyC was demonstrated to be responsible for this modification [111][124]. This structural feature conveys hydrophobicity to the N-terminus and is in line with the decreasing hydrophobicity
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Published 18 Jul 2024

Benzylic C(sp3)–H fluorination

  • Alexander P. Atkins,
  • Alice C. Dean and
  • Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

Graphical Abstract
  • , generated from reduction of tert-butyl benzoperoxoate (TBPB), selective benzylic HAT afforded the benzylic radical. Subsequent oxidation by Ir(IV) generated the benzylic cation that could be trapped by fluoride to afford the benzyl fluorides. An impressive scope with broad functional group tolerance
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Published 10 Jul 2024

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

  • Christopher Mairhofer,
  • David Naderer and
  • Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

Graphical Abstract
  • of the tert-butyl-containing β-ketoester 1a (Table 1 gives an overview of the most significant results obtained hereby). First experiments testing different oxidants in combination with Bu4NI (30 mol %) in 1,2-dichloroethane (DCE), a solvent that we found to be well-suited for oxidative α
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Published 05 Jul 2024

Towards an asymmetric β-selective addition of azlactones to allenoates

  • Behzad Nasiri,
  • Ghaffar Pasdar,
  • Paul Zebrowski,
  • Katharina Röser,
  • David Naderer and
  • Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

Graphical Abstract
  • investigated the generality of this protocol. As outlined in Scheme 2, differently substituted allenoates were reasonably well tolerated (see products 5a–d), albeit some erosion in enantioselectivity was observed when using a tert-butyl ester containing allenoate (product 5d). Various α-arylmethyl-substituted
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Published 04 Jul 2024

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

  • Lu Li,
  • Na Li,
  • Xiao-Tian Mo,
  • Ming-Wei Yuan,
  • Lin Jiang and
  • Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

Graphical Abstract
  • study began with the preparation of the (E)-2-arylidene-3-cyclohexenones 2 via DMAP-catalyzed elimination reaction of 2-cyclohexenone-MBH alcohols 1 and di-tert-butyl dicarbonate [22] as depicted in Scheme 2. Starting materials 2 were prepared in moderate to high yields. Next, we chose (E)-2
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Published 02 Jul 2024

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl2 and NH4SCN/KSeCN

  • Jialiang Wu,
  • Haofeng Shi,
  • Xuemin Li,
  • Jiaxin He,
  • Chen Zhang,
  • Fengxia Sun and
  • Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

Graphical Abstract
  • substituents (R2 and R3), albeit the reaction afforded product 2n in a much lower yield, possibly caused by steric congestion. In addition, when the aryl substituent of R1 was replaced with a tert-butyl group, this method also worked well to give product 2o in moderate yield. Notably, when the C3 and C5
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Published 28 Jun 2024

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

  • Xiu-Yu Chen,
  • Ying Han,
  • Jing Sun and
  • Chao-Guo Yan

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

Graphical Abstract
  • . Under the optimized reaction conditions, the scope of the reaction was developed by using various substrates. The results are summarized in Table 2. At first, several alkyl isocyanides such as cyclohexyl, tert-butyl and benzyl isocyanide have been successfully employed in the reaction. Dimethyl but-2
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Published 28 Jun 2024

Synthesis of cyclic β-1,6-oligosaccharides from glucosamine monomers by electrochemical polyglycosylation

  • Md Azadur Rahman,
  • Hirofumi Endo,
  • Takashi Yamamoto,
  • Shoma Okushiba,
  • Norihiko Sasaki and
  • Toshiki Nokami

Beilstein J. Org. Chem. 2024, 20, 1421–1427, doi:10.3762/bjoc.20.124

Graphical Abstract
  • the thioglycoside monomer 14 (Scheme 3) [17][18]. The electrochemical polyglycosylation of 14 was carried out in the presence of 2,6-di-tert-butyl-4-methylpyridine (DTBMP) to ensure the formation of a β-glycosidic bonds [19]. Although we could suppress formation of 1,6-anhydrosugar 15, cyclic
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Published 26 Jun 2024

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

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

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

Graphical Abstract
  • components, such as various acrylates, α,β-unsaturated acids, enones, enals, acrylamides, vinyl phosphonates, and vinyl sulfones. Various cesium salts of oxalates also performed well using this protocol. Isopropyl and tert-butyl groups present in an adjacent position of oxalates do not disturb the reaction
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Published 14 Jun 2024

Transition-metal-catalyst-free electroreductive alkene hydroarylation with aryl halides under visible-light irradiation

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

Beilstein J. Org. Chem. 2024, 20, 1327–1333, doi:10.3762/bjoc.20.116

Graphical Abstract
  • found to be suitable coupling partners. Aryl chloride 1a reacted with tert-butyl acrylate (2b) without any difficulty, providing 3ab in a high yield. Methacrylamide (2c) and acrylonitrile (2d) were transformed into the corresponding products in high yields, but with slightly lower Faradaic efficiency
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Published 10 Jun 2024

Synthesis of indano[60]fullerene thioketone and its application in organic solar cells

  • Yong-Chang Zhai,
  • Shimon Oiwa,
  • Shinobu Aoyagi,
  • Shohei Ohno,
  • Tsubasa Mikie,
  • Jun-Zhuo Wang,
  • Hirofumi Amada,
  • Koki Yamanaka,
  • Kazuhira Miwa,
  • Naoyuki Imai,
  • Takeshi Igarashi,
  • Itaru Osaka and
  • Yutaka Matsuo

Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109

Graphical Abstract
  • para-substituents were used and the reaction from FIDO to FIDS was found to tolerate both electron-donating and -withdrawing functional groups as shown in Table 2. It is well known that functional groups with larger steric hindrance can reduce intermolecular forces. Consequently, a tert-butyl
  • ) was determined by analyzing the onset of weight loss for these compounds. Tsub was lower for t-Bu-FIDO and t-Bu-FIDS, at 410 °C and 417 °C, respectively, than for C60, which began to sublimate at 460 °C (Table 3). The lower sublimation temperature was attributed to the steric hindrance of the tert
  • -butyl groups, which disrupted the π–π stacking between the fullerene cages. The slight difference in sublimation temperature between t-Bu-FIDO and t-Bu-FIDS might be due to the slightly higher electron density of the sulfur atom compared with the oxygen atom. Additionally, data on the degradation
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Published 31 May 2024

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

  • Manoel T. Rodrigues Jr.,
  • Aline S. B. de Oliveira,
  • Ralph C. Gomes,
  • Amanda Soares Hirata,
  • Lucas A. Zeoly,
  • Hugo Santos,
  • João Arantes,
  • Catarina Sofia Mateus Reis-Silva,
  • João Agostinho Machado-Neto,
  • Leticia Veras Costa-Lotufo and
  • Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

Graphical Abstract
  • decarboxylation directed by bismuth triflate at 100 °C. Synthesis of 3-aryl-1-indanones. aIsolated yield after purification using silica gel column chromatography. bReaction performed at 60 °C. cFrom tert-butyl Knoevenagel derivative. Basic protocol: The Knoevenagel product 9 (0.5 mmol), dry acetonitrile (2 mL
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Published 21 May 2024

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

  • Mohd Farhan Ansari,
  • Atul Kumar Maurya,
  • Abhishek Kumar and
  • Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

Graphical Abstract
  • way, alkylation of tert-butyl acetate with numerous alcohols was also tested using catalyst Mn18 (5 mol %), t-BuOK (2 equiv) in toluene at 100 °C for 4 h and gave moderate yields of 39 to 61%. Compared to the alkylation of amides, the alkylation of esters required higher catalyst and base loading
  • . However, the reaction proceeded at a low temperature and less reaction time (Scheme 51). In addition, Balaraman and co-workers reported the C-alkylation of unactivated amides and tert-butyl acetate using primary alcohols as alkylating agents catalyzed by an aliphatic PNP-Mn pincer catalyst [79]. Various
  • alcohols, including aliphatic alcohols, were coupled with N,N-dimethylacetamide using low catalyst loading (0.5 mol % Mn21) and t-BuOK as base (1.2 equiv) at 110 °C for 16 h and furnished the products in good yields (up to 88%). The alkylation of tert-butyl acetate with alcohols under the same reaction
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Published 21 May 2024
Graphical Abstract
  • substituents, respectively, were also attempted but without success. In these cases, the sterically congesting ortho isopropyl and tert-butyl groups stymie the Friedel–Crafts acylation step leading to diketone (Scheme 1). Experimental and computational studies of 1,3-diarylisoacenofurans Purified
  • isoacenofurans. Thus, unless there is a need for improved kinetic stabilization of the most reactive 1,3-carbons on the furan ring, there appears little benefit of utilizing highly hindered 2’,4’,6’-triisopropyl (compound 24) or 2’,4’,6’-tri-tert-butyl (compound 25) substituents, especially as these compounds
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Published 17 May 2024

Carbonylative synthesis and functionalization of indoles

  • Alex De Salvo,
  • Raffaella Mancuso and
  • Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

Graphical Abstract
  • the presence of Ni(dme)Cl2 (a nickel(II) chloride ethylene glycol dimethyl ether complex), dtbbpy (4,4-di-tert-butyl-2,2-dipyridyl), Zn(0) and ZnI2 in DMF at 120 °C [42] (Scheme 22). The nickel catalyst catalyzed the oxidative addition and CO insertion on aryl iodide compounds, while the Zn/ZnI2
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Published 30 Apr 2024

Innovative synthesis of drug-like molecules using tetrazole as core building blocks

  • Jingyao Li,
  • Ajay L. Chandgude,
  • Qiang Zheng and
  • Alexander Dömling

Beilstein J. Org. Chem. 2024, 20, 950–958, doi:10.3762/bjoc.20.85

Graphical Abstract
  • isocyanide component (Scheme 1). Aliphatic isocyanides, such as tert-octyl and tert-butyl isocyanide (1b and 1c) were well-tolerated in the Passerini-tetrazole reaction, leading to the corresponding tetrazole products in moderate to good yields of 74% and 52%, respectively. β-Cyanoethyl isocyanide (1d) was
  • also well tolerated providing a good yield (62%). The tolerability of different isocyanides, and the possibility to remove the cleavable isocyanides under different reaction conditions (acidic for the tert-octyl and tert-butyl isocyanide, basic for β-cyanoethyl isocyanide, or reductive for the benzyl
  • smoothly and provided moderate to excellent yields of 58–83%. Among this, the tert-octyl-substituted aldehyde exhibited excellent product transformation with a yield of 83% of 3e. Various isocyanides such as benzyl, phenylethyl, tert-octyl and tert-butyl isocyanides participated in the reaction with
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Published 29 Apr 2024

One-pot Ugi-azide and Heck reactions for the synthesis of heterocyclic systems containing tetrazole and 1,2,3,4-tetrahydroisoquinoline

  • Jiawei Niu,
  • Yuhui Wang,
  • Shenghu Yan,
  • Yue Zhang,
  • Xiaoming Ma,
  • Qiang Zhang and
  • Wei Zhang

Beilstein J. Org. Chem. 2024, 20, 912–920, doi:10.3762/bjoc.20.81

Graphical Abstract
  • the reported procedures [41], the Ugi-azide reaction of 2-bromobenzaldehyde (1a, 1 mmol), allylamine hydrochloride (2, 1 mmol), trimethylsilyl azide (3, 1 mmol) and tert-butyl isocyanide (4a, 1 mmol) in MeOH at 40 °C for 24 h afforded 1,5-DS-1H-T 5a in 92% yield after chromatography purification. Our
  • mmol), trimethylsilyl azide (3, 1 mmol), and tert-butyl isocyanide (4a, 1 mmol) was stirred in MeOH at 40 °C for 24 h, and after the reaction was completed, the solvent was evaporated under vacuum to give crude Ugi adduct 5a which was used for the intramolecular Heck reaction without further
  • . Experimental General procedure for the synthesis of Ugi-azide adduct 5a A solution of 2-bromobenzaldehyde 1 (1 mmol, 1 equiv), allylamine hydrochloride (2, 1 mmol, 1 equiv), trimethylsilyl azide (3, 1 mmol, 1 equiv) and tert-butyl isocyanide 4a (1 mmol, 1 equiv) in MeOH (5 mL) with Et3N (1.5 mmol) was heated
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Published 23 Apr 2024

(Bio)isosteres of ortho- and meta-substituted benzenes

  • H. Erik Diepers and
  • Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

Graphical Abstract
  • -workers, and was accessed over 8 steps from diene 161 (Scheme 17A) [51]. Diels–Alder reaction of diene 161 and di-tert-butyl azodicarboxylate (160) followed by palladium-assisted elimination of acetic acid gave diene 162. A sequence of 4π-electrocyclisation and electrophilic transcarbamation (to 163
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Published 19 Apr 2024

Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

  • Ke Jiang,
  • Cheng Pan,
  • Limin Wang,
  • Hao-Yang Wang and
  • Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

Graphical Abstract
  • 3au and 3av were produced in 34% and 39% yields, respectively, in which methoxy and tert-butyl groups were located in the para position to the hydroxy group (Table 2, entries 20 and 21). In the case of 3al, the mono-arylation of naphthol generated 3al’ in 20% isolated yield, which is the reason for
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Published 18 Apr 2024

Advancements in hydrochlorination of alkenes

  • Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

Graphical Abstract
  • carbenium ions are highly energetic species which tend to react unselectively according to the reactivity–selectivity principle. In contrast, MH HAT produces relatively stable radicals which is demonstrated by, e.g., the strong difference of heat of formation of the tert-butyl radical and cation (Figure 7B
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Published 15 Apr 2024

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

  • Julien Borrel and
  • Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

Graphical Abstract
  • work [45], and will be only shortly described in a summarized form (Scheme 3). Styrene substituted with a tert-butyl at the para position afforded 4b in 78% yield. Using a styrene bearing a sterically hindered aryl afforded 4c in a similar yield. Homopropargylic azides possessing oxygen substituents
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Published 03 Apr 2024

HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines

  • Luan A. Martinho and
  • Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2024, 20, 628–637, doi:10.3762/bjoc.20.55

Graphical Abstract
  • our hands, when we tried to reproduce the reaction between 2-aminopyridine (1a), benzaldehyde (2), and tert-butyl isocyanide (3a), following in detail the reported protocol using exactly the same reaction conditions, the reaction failed completely in 20 minutes (followed by TLC) and after 72 h only 46
  • -Aminopyridine (1a), 4-nitrobenzaldehyde (2a), and tert-butyl isocyanide (3a) were chosen as model substrates and different conditions were screened (Table 1). Glycerol, a green and sustainable solvent, was tried first, but unfortunately, the expected intense orange solid product 4a was obtained in low yields
  • -position gave moderate product yields (4c and 4d). Furthermore, cyclohexyl isocyanide gave higher yields compared to tert-butyl isocyanide. Ortho-substituted aromatic aldehydes were very efficient, regardless the type of substituents used, and good to excellent yields (74–99%) of products 4k–r were
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Published 19 Mar 2024

Switchable molecular tweezers: design and applications

  • Pablo Msellem,
  • Maksym Dekthiarenko,
  • Nihal Hadj Seyd and
  • Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Graphical Abstract
  • tweezers with tert-butyl groups positioned farther from the salphen via alkyne spacers were synthesized [42]. While, like in the parent tweezers 12, no intercalation of aromatic guests was observed in the closed form, strong intramolecular and intermolecular Pt–Pt bonds were achieved in the solid state
  • ]. In the neutral state, the tweezers 34 adopt an anti-conformation because of steric hindrance between the N–H and the tert-butyl groups. Again, the N–H proton of the indole can bind to anions through hydrogen bonds and causes the system to adopt a cis-conformation, closing the tweezers. This closed
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Published 01 Mar 2024
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