Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• interaction greatly affected the chemical properties. They also reported that complexes that had higher oxidation potential and went through irreversible oxidation were not good catalysts for the oxidation of benzyl alcohol to benzaldehyde (0–30% yields, e.g., PhPhCuO.S.2, O.S.x signifies oxidation state and

• x increases with the removal of electrons). On the other hand, complex t-BuPhCuO.S.2, showing a reversible oxidation behavior very efficiently performs dehydrogenation of benzyl alcohol with low catalyst loading (0.1 mol %) and high turnover numbers (TONs up to 184). Besides the oxidation of benzyl

• reaction of CuII complex 6A with dioxygen to generate a CuII superoxide intermediate 6B. The electron needed to reduce O2 to superoxide is provided by the redox-active ligand. Subsequent coordination of benzyl alcohol results in the formation of species 6C, which undergoes a H-atom abstraction step to form

Diversity-oriented synthesis of spirothiazolidinediones and their biological evaluation

• Sambasivarao Kotha,
• Gaddamedi Sreevani,
• Lilya U. Dzhemileva,
• Milyausha M. Yunusbaeva,
• Usein M. Dzhemilev and
• Vladimir A. D’yakonov

Beilstein J. Org. Chem. 2019, 15, 2774–2781, doi:10.3762/bjoc.15.269

• spirothiazolidinediones via a [2 + 2 + 2] cyclotrimerization reaction and the derivatives were further functionalized through DA chemistry and click reaction. Using flow cytometry, it was shown for the first time that the new benzyl alcohol derivatives of thiazolidine-2,4-dione generated here are efficient apoptosis

• strategy with propargyl halides. We have also shown the synthesis of linearly fused spirocyclic alcohol derivatives of thiazolidinedione using Wilkinson’s catalyst and these compounds were tested for their anticancer activity. We have shown for the first time that the new benzyl alcohol derivatives of

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• corresponding carboxylic acid followed by hydrogenolysis with H2/Pd-C led in spontaneous lactonization to give the key butenolide 66. Oxidation of 66 with CrO3/AcOH–H2O, followed by saponification and reduction afforded known benzyl alcohol 46 (19% from 66). Then, phenol 46 was converted to the corresponding

A metal-free approach for the synthesis of amides/esters with pyridinium salts of phenacyl bromides via oxidative C–C bond cleavage

• Kesari Lakshmi Manasa,
• Yellaiah Tangella,
• Namballa Hari Krishna and
• Mallika Alvala

Beilstein J. Org. Chem. 2019, 15, 1864–1871, doi:10.3762/bjoc.15.182

• synthesis. Comparison of our work with previous studies. Scope of pyridinium salts and benzylamine substrates. Reaction conditions: 1 (1 mmol), 2 (1 mmol), base (2.5 mmol), solvent (5 mL), 80 °C, 8 h. Isolated yields are given in parentheses. Scope of pyridinium salts and benzyl alcohol substrates. Reaction

Robust perfluorophenylboronic acid-catalyzed stereoselective synthesis of 2,3-unsaturated O-, C-, N- and S-linked glycosides

• Madhu Babu Tatina,
• Xia Mengxin,
• Rao Peilin and
• Zaher M. A. Judeh

Beilstein J. Org. Chem. 2019, 15, 1275–1280, doi:10.3762/bjoc.15.125

• the reaction of 3,4,6-tri-O-acetyl-D-glucal (1a) with benzyl alcohol (2) in the presence of 20 mol % of arylboronic acids in different solvents (Table 1, entries 1–6). Phenylboronic acid failed to promote the reaction in several solvents and the starting glucal 1a was recovered unchanged (Table 1

• blocks especially for natural product synthesis [36][37][38][39][40]. Therefore, we used the perfluorophenyl boronic acid catalyst in the reaction between 2,3,4,6-tetra-O-acetyl-D-glucal (1a) and benzyl alcohol, n-butyl alcohol, cyclohexyl alcohol and p-toluenethiol (Figure 2). Gratifyingly, the reaction

• -acetyl-D-glucal (1a) with benzyl alcohol (2). Supporting Information Supporting Information File 276: Experimental data and copies of 1H and 13C NMR spectra of glycosides 3a–u, 5a–d and 7a–h are provided. Acknowledgements We thank Nanyang Technological University, Singapore for financial help (RG 13/18).

Mechanochemical synthesis of poly(trimethylene carbonate)s: an example of rate acceleration

• Sora Park and
• Jeung Gon Kim

Beilstein J. Org. Chem. 2019, 15, 963–970, doi:10.3762/bjoc.15.93

• ). Representative procedure for mechanochemical solvent-free poly(trimethylene carbonate) synthesis (Table 1, entry 11). Three 7 mm stainless-steel milling balls were placed in a 10 mL stainless-steel milling container and trimethylene carbonate (0.100 g), benzyl alcohol (1.02 µL), and DBU (1.46 µL) were added. The

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• achieved from benzyl alcohol using a Br+ source as the catalyst (Figure 16). In the reaction pot subcomponents such as benzaldehydes and H+ were formed which further participated in a cascade transformation to give dihydropyrimidones 29. Dynamic combinatorial chemistry and mechano-milling Dynamic

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• , reaction with pyrrolidine, imidazole, methanol, allyl alcohol, benzyl alcohol and 9-fluorenemethanol (FmOH) provided the corresponding urea 30, N-carbamoyl imidazole 31 and carbamates 32–35, respectively, in good yields (69–80%). The reaction of isocyanate 28 with tert-butanol was sluggish even by heating

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• trifluoride etherate-catalyzed reaction of 95 with benzyl alcohol induces first opening of the 5-membered ring to form a benzyl ester and later the cleavage of the 3-membered ring to give a vicinal N-Cbz aminoalcohol with inversion of configuration. However, the reaction mixture (1:1) consists of the

• protected 3,4-dihydroxy-L-glutamic acid 96 and the respective γ-lactone 97 formed from 96 in the presence of acids. Benzyl alcohol was selected to refrain from decomposition of the final amino acids during the acid hydrolysis of, e.g., methyl esters [99] since for a mixture of 96 and 97 hydrogenolysis

• give dimethyl ester 98 (Scheme 25). Silver oxide-promoted methylation introduces a MeO-C4 unit. Regioselective aziridine ring opening in 99 was then carried out in the known way with benzyl alcohol or methanol to produce substituted dimethyl L-glutamates 100 and 101. To ensure clean deprotection in the

Nucleofugal behavior of a β-shielded α-cyanovinyl carbanion

• Rudolf Knorr and
• Barbara Schmidt

Beilstein J. Org. Chem. 2018, 14, 3018–3024, doi:10.3762/bjoc.14.281

• comparison with 7 and benzyl alcohol; IR (KBr): 3404 (O–H), 2971, 2228 (C≡N), 1487, 1458, 1368, 1052, 751, 716 cm−1; anal. calcd for C22H23NO (317.4): C, 83.24; H, 7.30; N, 4.41; found: C, 83.39; H, 7.33; N, 4.48. 3´-Cyclopropyl-3´-hydroxy-2´-(1,1,3,3-tetramethylindan-2-ylidene)propionitrile (9). Using the

Synthesis of mono-functionalized S-diazocines via intramolecular Baeyer–Mills reactions

• Miriam Schehr,
• Daniel Hugenbusch,
• Tobias Moje,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2018, 14, 2799–2804, doi:10.3762/bjoc.14.257

• functionalized with a carboxylic acid 4 or a benzyl alcohol 5 could not be obtained using the reductive azo coupling. For the benzyl alcohol 5 a variety of different, unidentified byproducts formed and in case of the carboxylic acid 4 only the starting material was retrieved. We now present a reliable one-pot

• hydroxylamine and subsequently in situ oxidized to the nitroso compound using iron(III) chloride. After addition of acetic acid the reaction was allowed to proceed for several hours at room temperature to form the azo bond. For the benzyl alcohol-functionalized S-diazocine 5, the carboxylic acid of the

• precursors for the incorporation in photopharmacophores using cross-coupling, peptide coupling or further functionalization methods such as nucleophilic substitution reaction of the benzyl alcohol 5. The yield determining steps prior to the Baeyer–Mills reaction are the formation of the hydroxylamine with

Quinolines from the cyclocondensation of isatoic anhydride with ethyl acetoacetate: preparation of ethyl 4-hydroxy-2-methylquinoline-3-carboxylate and derivatives

• Nicholas G. Jentsch,
• Jared D. Hume,
• Emily B. Crull,
• Samer M. Beauti,
• Amy H. Pham,
• Julie A. Pigza,
• Jacques J. Kessl and
• Matthew G. Donahue

Beilstein J. Org. Chem. 2018, 14, 2529–2536, doi:10.3762/bjoc.14.229

• in 91% yield. The ethyl ester was then smoothly reduced with DIBAL to the benzyl alcohol. While the in-process analysis (TLC and HPLC) indicated quantitative reduction, the isolated yields from the reductions were only poor to modest despite utilizing standard workup conditions with sodium potassium

Synthesis of a leopolic acid-inspired tetramic acid with antimicrobial activity against multidrug-resistant bacteria

• Luce Mattio,
• Loana Musso,
• Leonardo Scaglioni,
• Andrea Pinto,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2018, 14, 2482–2487, doi:10.3762/bjoc.14.224

• tosylate in the presence of 18-crown-6 ether [15]. The synthesis of benzyl tosylate was accomplished using benzyl alcohol and freshly recrystallized p-toluenesulfonyl chloride in the presence of anhydrous trimethylamine and DMAP, in anhydrous dichloromethane [25]. At this stage, all attempts to obtain the

• , afforded the desired O-alkyltetramic acid 13 in 30% yield. The synthesis of the activated ureido fragment was achieved in four steps from suitably protected L-valine and L-phenylalanine. The benzyl protection of L-phenylalanine (14) was carried out with PTSA and benzyl alcohol in toluene and the ester 15

• tosylate, KHMDS 0.5 M in toluene, crown ether 18-crown-6, THF, 0 °C to rt, 2.5 h, 30% over two steps. Synthesis of dipeptide L-Phe-L-Val intermediate 20. Reagents and conditions: a) PTSA·H2O, benzyl alcohol, toluene, reflux, 10 h, 70%; b) HClO4, tert-butyl acetate, 0 °C, 1 h, then rt, 20 h, 75%; c

One-pot synthesis of epoxides from benzyl alcohols and aldehydes

• Edwin Alfonzo,
• Jesse W. L. Mendoza and
• Aaron B. Beeler

Beilstein J. Org. Chem. 2018, 14, 2308–2312, doi:10.3762/bjoc.14.205

• benzyl alcohol (1) in the presence of slight excess of tetrafluoroboric acid in diethyl ether (HBF4·Et2O) and tetrahydrothiophene (THT). Notably, the use of acetonitrile (MeCN) as a solvent was critical for maintaining a homogeneous reaction and a successful outcome. We also observed that sodium hydride

• -rich alcohol 4 showed faster reaction rates and yields, presumably due to faster and more efficient formation of the sulfonium salt through a para-quinonemethide (p-QM) intermediate. Furthermore, the lower diastereomeric ratios (dr) observed for benzyl alcohol 4 may be due to competing p-QM formation

Cobalt-catalyzed peri-selective alkoxylation of 1-naphthylamine derivatives

• Jiao-Na Han,
• Cong Du,
• Xinju Zhu,
• Zheng-Long Wang,
• Yue Zhu,
• Zhao-Yang Chu,
• Jun-Long Niu and
• Mao-Ping Song

Beilstein J. Org. Chem. 2018, 14, 2090–2097, doi:10.3762/bjoc.14.183

• . Cyclopropylmethanol (2o), cyclohexylmethanol (2p), and adamantanemethanol (2q) were compatible with the transformation (45–56%). Moreover, an aliphatic ether and benzyl alcohol were proved to be effective coupling partners to provide 3ar and 3as in 68% and 70% yields, respectively. Compared with Co-catalyzed

Heterogeneous acidic catalysts for the tetrahydropyranylation of alcohols and phenols in green ethereal solvents

• Ugo Azzena,
• Massimo Carraro,
• Gloria Modugno,
• Luisa Pisano and
• Luigi Urtis

Beilstein J. Org. Chem. 2018, 14, 1655–1659, doi:10.3762/bjoc.14.141

• 4-(tetrahydro-2H-pyran-2-yloxymethyl)benzyl alcohol (4fb). Synthesis of 2-(2-phenylethoxy)tetrahydro-2H-pyran (3a). Supporting Information Supporting Information File 256: Full experimental details, copies of IR spectra of fresh and recycled NH4HSO4@SiO2 and copies of 1H and 13C NMR spectra.

Mild and selective reduction of aldehydes utilising sodium dithionite under flow conditions

• Nicole C. Neyt and
• Darren L. Riley

Beilstein J. Org. Chem. 2018, 14, 1529–1536, doi:10.3762/bjoc.14.129

• coil mounted on a heating block and a back pressure regulator fitted at the output flow stream. Reagents were introduced through two 10 mL injection loops (Figure 2). Optimisation under flow conditions The flow reduction was initially optimised for the conversion of benzaldehyde to benzyl alcohol. The

• coil reactor (Table 2, Figure 3). In order to better compare the flow and batch processes the reduction of benzaldehyde was repeated in a seal-tube vessel superheated to 110 °C with a reaction time of 64 min to match that of the optimised flow process. In this instance a 43% conversion to benzyl

• alcohol was observed, indicating that under flow conditions, the simple superheating of the solvent was only partly responsible for the increased rate of reaction and that in all likelihood the improved mixing of the reagent streams also plays an important role. Further reduction of the residence time

Preparation, structure, and reactivity of bicyclic benziodazole: a new hypervalent iodine heterocycle

• Akira Yoshimura,
• Michael T. Shea,
• Cody L. Makitalo,
• Melissa E. Jarvi,
• Gregory T. Rohde,
• Akio Saito,
• Mekhman S. Yusubov and
• Viktor V. Zhdankin

Beilstein J. Org. Chem. 2018, 14, 1016–1020, doi:10.3762/bjoc.14.87

• have investigated the analogous oxidatively assisted coupling reaction of carboxylic acids 9 with alcohols 10 or amine 12 using benziodazole 7a under similar conditions (Scheme 3). The reaction of butyric acid (9a) with benzyl alcohol (10a) using benziodiazole 7a in the presence of triphenylphosphine

• and N,N-dimethyl-4-aminopyridine (DMAP) in chloroform solution under reflux conditions afforded the desired product 11a in good yield. As expected, the reactions of benzoic acid (9b) with benzyl alcohol (10a) or 1-pentanol (10b) under the same conditions gave the corresponding esters 11b or 11c in

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

• ]. This type of linkers/spacers offers the capability to release the active drug after simultaneous cascade reactions, as shown in Figure 5. Para-amino benzyl alcohol (PABC; colored in red) is a representative example that can be connected in the amino group via an amide bond to an enzyme-hydrolyzable

Volatiles from the xylarialean fungus Hypoxylon invadens

• Jeroen S. Dickschat,
• Tao Wang and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 734–746, doi:10.3762/bjoc.14.62

• index and best matching mass spectrum (Table 5). Notably, a common biosynthesis for all the identified aromatic compounds can be assumed that further strengthens their structure elucidations (Scheme 1). Starting from 11, an oxidation step at the 2-methyl group (red) could lead via the benzyl alcohol

Biocatalytic synthesis of the Green Note trans-2-hexenal in a continuous-flow microreactor

• Morten M. C. H. van Schie,
• Tiago Pedroso de Almeida,
• Gabriele Laudadio,
• Florian Tieves,
• Elena Fernández-Fueyo,
• Timothy Noël,
• Isabel W. C. E. Arends and
• Frank Hollmann

Beilstein J. Org. Chem. 2018, 14, 697–703, doi:10.3762/bjoc.14.58

• Michaelis–Menten dependency of the enzyme activity (Figure 1). Apparent KM and kcat values of approximately 1 mM and 22 s−1 were estimated, respectively. These values are in the same order of magnitude as those for benzyl alcohol substrates reported previously [29]. The slightly decreasing enzyme activity

Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides

• Lingjun Xu,
• Shuwen Han,
• Linjie Yan,
• Haifeng Wang,
• Haihui Peng and
• Fener Chen

Beilstein J. Org. Chem. 2018, 14, 309–317, doi:10.3762/bjoc.14.19

• different alcohols (Table 3). Excellent yields with high enantioselectivities were obtained in all cases. The sterically more bulky 2-propanol worked well in this reaction. Allylic alcohol, benzyl alcohol and cinnamyl alcohol were also well compatible in this bifunctional organocatalysis conditions to

Stereochemical outcomes of C–F activation reactions of benzyl fluoride

• Neil S. Keddie,
• Pier Alexandre Champagne,
• Justine Desroches,
• Jean-François Paquin and
• David O'Hagan

Beilstein J. Org. Chem. 2018, 14, 106–113, doi:10.3762/bjoc.14.6

• reduced under Noyori’s conditions [12] using (S,S)-Ru(DPEN)2 as catalyst and [2H2]-formic acid as the deuterium source. This afforded the corresponding 7-[2H1]-(S)-benzyl alcohol ((S)-3) in moderate yield (81%) and high ee (95%), as evidenced by 2H-PBLG-NMR. Benzyl alcohol 3 was converted to the

Electron-deficient pyridinium salts/thiourea cooperative catalyzed O-glycosylation via activation of O-glycosyl trichloroacetimidate donors

• Mukta Shaw,
• Yogesh Kumar,
• Rima Thakur and
• Amit Kumar

Beilstein J. Org. Chem. 2017, 13, 2385–2395, doi:10.3762/bjoc.13.236

• ), benzyl alcohol (2c), 4-methoxy benzyl alcohol (2d), and secondary alcohols, e.g., cyclohexanol (2e), cyclopentanol (2f) produced their corresponding glucosides 5b–f in 78–88% yields and with moderate α-selectivity (Table 2, entries 1–5). It is important to note that, when a halogenated primary alcohol

Mechanically induced oxidation of alcohols to aldehydes and ketones in ambient air: Revisiting TEMPO-assisted oxidations

• Andrea Porcheddu,
• Evelina Colacino,
• Giancarlo Cravotto,
• Francesco Delogu and
• Lidia De Luca

Beilstein J. Org. Chem. 2017, 13, 2049–2055, doi:10.3762/bjoc.13.202

• . Ideally, a dispersant should not interfere with the oxidation reaction, and should be inexpensive and eco-friendly, if possible. As a first choice, we dispersed benzyl alcohol (1b) on alumina and silica gel. However, the reaction did not go to completion. In contrast, it proceeded smoothly (10 min) and in

• aromatic ring of the benzyl alcohol were also viable, giving the corresponding aromatic aldehydes in high yields regardless of the electronic nature of their substituents (aldehydes 2g–k in Scheme 3). Surprisingly, and contrary to Stahl’s original solution procedure [24], the oxidation of 2-hydroxybenzyl

• was sealed and ball-milled for 1 min. Then, benzyl alcohol (216.3 mg, 207 μL, 2.0 mmol), NaCl (1.0 g) together with other two zirconia balls (12 mm Ø) were added and the reaction mixture was subjected to grinding for further 10 minutes overall (two cycles of 5 minutes each). The first milling cycle