Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• cycloadduct 3a. 3-Azabicyclo[3.1.0]hexane derivative 3a was obtained after recrystallization from MeOH in yields 67, 70, and 61%, respectively (Table 1, entries 2–4). In contrast to aprotic solvents, alcohols such as methanol (MeOH) and ethanol (EtOH) were absolutely unsuitable for carrying out this reaction

• owing to incompatibility of 1,3-dipole 1 with this medium (Table 1, entries 5 and 6). PRP (1) was found to immediately undergo a proton transfer reaction with alcohols, converting it into the conjugate base (Ruhemann's purple). When using dichloromethane as a solvent, the reaction took place at reflux

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• ][28][29][30][31]. More recently, Paradisi and co-workers disclosed a more general access to a variety of esters with mainly fruity and floral odorants by transesterification of acyl donors of structure 12 to the corresponding alcohols 11 using an immobilized transferase obtained from Mycobacterium

• smegmatis (Scheme 4) [32]. A solution of the acyl donor 12 in ethyl acetate and an aqueous buffer solution of the corresponding alcohols 11 are mixed in a T-piece and the resulting segmented flow is pumped through a packed-bed reactor containing the immobilized transferase. The reaction mixture is directly

• esters with mainly fruity odor profiles are obtained in moderate to excellent yields. Some selected esters (14–16) and their odor profiles are shown in Scheme 4 [32]. Related methods for the esterification of natural occurring alcohols, such as geraniol, utilizing immobilized enzyme-catalysis in packed

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• oxidations of alcohols to aldehyes or ketones using gold nanoparticles in the presence of oxygen gas or atmospheric air was achieved by modifying the silica shell of nanostructured MagSilicaTM with gold nanoparticles (Scheme 12, case B). After heating these modified SPIONs in an electromagnetic field, a

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• Trichoderma citrinoviride produces structurally diverse secondary metabolites including diterpenes [1][2], alkaloids [3], sorbicillinoids [4][5], long chain alcohols [6], and cyclonerane sesquiterpenes [7]. Some of them display antibacterial [1][2][7], cytotoxic [3], anti-inflammatory [4], and antimicroalgal

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

• Md Imran Hossain,
• Md Imdadul H. Khan,
• Seong Jong Kim and
• Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

• and γ-amino alcohols [1]. Isoxazoles, appearing in 33 patents from the year 2016 to 2018 [3], are an important drug class due to their wide range of biological activities, such as anticancer [5], antibiotic [6][7], antimicrobial [8], antifungal [9], and anti-inflammatory [10]. Therefore, new methods

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

•  2). The bulky (R2 = t-Bu) or chiral (R2 = ʟ-menthyl or (−)-bornyl) alkoxy groups (derived from relatively inexpensive and readily available alcohols) were introduced into the carbamate moiety instead of an ethyl group as in aldehydes 15 and 19. Here, the influence of this structural modification of

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• Ol'ga G. Volostnykh Olesya A. Shemyakina Anton V. Stepanov Igor' A. Ushakov A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky Str., 664033 Irkutsk, Russian Federation 10.3762/bjoc.18.44 Abstract The reaction of bromopropargylic alcohols

• bromopropargylic alcohols and Cs2CO3. Keywords: acetylenic alcohol; bromoacetylene; 1,3-dioxolan-2-one; phenols; phenoxyketone; Introduction Due to the relative stability, ease of handling and the presence of reactive sites, bromoacetylenes are widely applied in synthetic organic chemistry. They are known to be

• bromopropargylic alcohols under the reported conditions. The bromopropargylic alcohols are readily available from acetylenic alcohols and hypobromite [22] or N-bromosuccinimide [23]. The presence of the hydroxy group expands the synthetic potential of these bromoacetylenes. Thus, we have recently demonstrated a

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• reactions involving the formation of cationic intermediate species [41] like water elimination from an alcohol to provide the corresponding alkene, the isomerization of β-pinene and α-pinene and the cyclization of (S)-citronellal to secondary alcohols. The key point to interpret the action of the capsule in

• performed extra control experiments for each investigated reaction also only with the more symmetrical and less acidic capsule A to underline the effect of the water content on the catalytic activity. (S)-Citronellal isomerization to cyclic secondary alcohols (S)-Citronellal is an enantiopure monoterpenoid

• diastereoisomeric secondary alcohols (Scheme 2). The reaction of (S)-citronellal in the presence of 10 mol % of 16 at 60 °C was monitored by 1H NMR observing the rapid disappearance of the triplet signal at 9.78 ppm relative to the aldehyde hydrogen atom and consequent increase of the signals at 4.9 ppm relative to

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• more reactive alkynes and allylic alcohols. Both the microenvironment of the supramolecular catalyst and the steric profile of the substrate were responsible for the site-selectivity of hydrogenation. This beautiful work of a supramolecular-mediated catalytic site-selective reaction exhibited the

Regioselectivity of the S_EAr-based cyclizations and S_EAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles

• Jonali Das and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33

• 2021, Deng et al. showcased an unprecedented iridium-catalyzed asymmetric [4 + 3] cycloaddition of racemic 4-indolyl allylic alcohols 22 with α-imino esters 23 as azomethine ylide precursors to afford azepino[3,4,5-cd]indoles 24 in good yields and with complete regioselectivity and generally excellent

• cyclization leading to the formation of polycyclic azepino[5,4,3-cd]indoles. Synthesis of azepino[3,4,5-cd]indoles via iridium-catalyzed asymmetric [4 + 3] cycloaddition of racemic 4-indolyl allylic alcohols with azomethine ylides. Aldimine condensation/1,6-hydride transfer/Mannich-type cyclization cascade of

Synthesis of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines and investigation of their fungistatic activity

• Anna V. Korotina,
• Svetlana G. Tolshchina,
• Rashida I. Ishmetova,
• Natalya P. Evstigneeva,
• Natalya A. Gerasimova,
• Natalya V. Zilberberg,
• Nikolay V. Kungurov,
• Gennady L. Rusinov,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2022, 18, 243–250, doi:10.3762/bjoc.18.29

• -disubstituted 1,2,4,5-tetrazines bearing amidine fragments. It is shown that the heterocyclic systems obtained can be modified easily at C(3) position in the reactions with aliphatic alcohols and amines. Also, the reactivity of [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines towards CH-active compounds has been

Synthesis and late stage modifications of Cyl derivatives

• Phil Servatius and
• Uli Kazmaier

Beilstein J. Org. Chem. 2022, 18, 174–181, doi:10.3762/bjoc.18.19

• degree of variability for the generation of small libraries, in our case of Cyl-1 derivatives. Chiral allylic alcohols are easily accessible, either via kinetic resolution of racemic alcohols [46][47], asymmetric catalysis [48], or from chiral pool materials, such as threitol 1 [49]. Using the last

Asymmetric organocatalytic Michael addition of cyclopentane-1,2-dione to alkylidene oxindole

• Estelle Silm,
• Ivar Järving and
• Tõnis Kanger

Beilstein J. Org. Chem. 2022, 18, 167–173, doi:10.3762/bjoc.18.18

• to synthesise indoloquinolizidines [5]. Moreover, six-membered and five-membered cyclic 1,3-diketones have been investigated in reactions with acetates of nitroalkenes [6], cyanoacrylates and benzylidene malononitriles [7], ortho-hydroxy-benzhydryl alcohols [8], α,β-unsaturated pyrazolamides [9] and

Chemoselective N-acylation of indoles using thioesters as acyl source

• Tianri Du,
• Xiangmu Wei,
• Honghong Xu,
• Xin Zhang,
• Ruiru Fang,
• Zheng Yuan,
• Zhi Liang and
• Yahui Li

Beilstein J. Org. Chem. 2022, 18, 89–94, doi:10.3762/bjoc.18.9

• efficient method for the synthesis of N-acylindoles becomes much attractive [9][10][11][12]. In 2009, Scheidt developed a dehydrogenative approach using indoles and alcohols catalyzed by tetrapropylammonium perruthenate [13] (Scheme 1, A1). In 2012, Sarpong successfully carried out chemoselective acylation

Efficient synthesis of ethyl 2-(oxazolin-2-yl)alkanoates via ethoxycarbonylketene-induced electrophilic ring expansion of aziridines

• Yelong Lei and
• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 70–76, doi:10.3762/bjoc.18.6

• synthesis of oxazoline derivatives [11][12]. They mainly include (1) cyclization of 2-amidoethyl halides or sulfonates, which are prepared from carboxylic acid derivatives and vicinal amino alcohols [8][9][10] (Scheme 1a); (2) direct condensation of carboxylic acid derivatives or nitriles with vicinal amino

• alcohols [13][14][15] (Scheme 1a); (3) oxidative condensation of aldehydes with vicinal amino alcohols [16] (Scheme 1b); (4) cyclization of N-allylamides in the presence of electrophilic reagents or radical initiators or catalysts [17] (Scheme 1c); (5) direct synthesis from alkenes and amides or nitriles

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• single-step. The proposed mechanism is depicted in Scheme 26. Xiao and co-workers developed an environmentally benign strategy for the oxidative cyanation of differently substituted alcohols using a manganese oxide nanorod-supported ruthenium catalyst (Scheme 27) [49]. They also evaluated the efficiency

• of other metals such as Au, Pt, Pd, Rh, Ag, and Fe and found that they were less efficient compared to Ru. The benzylic alcohols showed higher reactivity than aliphatic alcohols towards this methodology. Moreover, this protocol worked well for differently substituted heterocyclic alcohols and

• catalyst. Synthesis of cyanated isoxazolines from alkenyl oximes catalyzed by [RuCl2(p-cymene)]2 in the presence of tert-butyl nitrite. Proposed mechanism for the synthesis of cyanated isoxazolines from alkenyl oximes. Oxidative cyanation of differently substituted alcohols. Cyanation of tertiary amines

A photochemical C=C cleavage process: toward access to backbone N-formyl peptides

• Haopei Wang and
• Zachary T. Ball

Beilstein J. Org. Chem. 2021, 17, 2932–2938, doi:10.3762/bjoc.17.202

• -nitroaryl compounds. Various 2-nitrobenzyl derivatives are used to photocage heteroatom functional groups, including alcohols, amines, carboxylic acids, and phosphates [11]. Typical photochemical pathways result in cleavage of a benzylic C–X bond following initial benzylic H-atom abstraction [11][13]. In

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• -disubstituted counterparts, perhaps due to the generation of the more stable 3° radical intermediate. In the following year, Song and Li reported a reaction shortcut for the carbonyl-arylation of N-arylacrylamides 60 through the in-situ oxidation of alcohols 67 (Scheme 11) [84]. Under the optimized reaction

• conditions, both primary and secondary alcohols are oxidized to the corresponding aldehyde/ketone, so the chronology of the addition remains unclear whether the reaction proceeds exclusively via an alkyl radical followed by subsequent oxidation, an acyl radical, or a combination of both. Further, slight

• alcohols 67 and aliphatic acids 173 (Scheme 37) [144]. Through a DCC-mediated dehydrogenative condensation with hydroperoxides, carboxylic acids could generate alkyl diacyl peroxides and peresters in situ. Decarboxylation followed by radical addition across the alkene 108 would generate a succeeding alkyl

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

• Lukáš Ďurina,
• Anna Ďurinová,
• František Trejtnar,
• Ľuboš Janotka,
• Lucia Messingerová,
• Jana Doháňošová,
• Ján Moncol and
• Róbert Fischer

Beilstein J. Org. Chem. 2021, 17, 2781–2786, doi:10.3762/bjoc.17.188

• formation. Since the aqueous tungstic acid-catalyzed hydrogen peroxide epoxidations of monosubstituted allylic alcohols usually proceed in anti (erythro) stereoselective fashion [32], we propose that the high syn selectivity can be attributed to the presence of the unprotected hydroxy group in the

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• atroposelective synthesis of axially chiral biarylamino alcohols from the reaction of quinone ester (3) and various 2-naphthylamines 4. In the presence of CPA 2, the axially chiral biarylamino alcohols 5 were obtained in moderate to good yields (up to 85%) and high to excellent enantioselectivities (up to 99% ee

• enantioselectivity (91:9 to 98:2 er, Scheme 15) [65]. In addition, the authors also succeeded in preparing naphthylindoles 46, which exhibit both axial and central chirality, through the addition reaction of racemic naphthylindoles 42 and o-hydroxybenzyl alcohols 45 using chiral phosphoric acid CPA 13. This reaction

• -trifluoromethylpropargyl alcohol are very important for the reaction. Li and co-workers developed a chiral phosphoric acid-catalyzed asymmetric remote 1,8-conjugate addition of thiazolones 111 and azlactones 112 to propargyl alcohols 110 for the synthesis of the chiral allenes 113 and 114, respectively. In the presence of

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2668–2679, doi:10.3762/bjoc.17.181

• cyclization of primary alcohols like 2k has been successfully utilized in the synthesis of fluorenones and azafluorenones [37], however, the authors used TBHP in n-decane. We repeated the reaction for primary amine 2a, primary alcohol 2k, as well as aldehyde 2l with TBHP in n-decane and obtained fluorenone (3

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• aliphatic alcohols. In 2015, Ackermann’s group [88] disclosed the visible light-induced copper-catalyzed arylation of azoles. In this case, the mechanistic studies revealed that amino acid ligands accelerated the cross-coupling (Scheme 22). In 2020, a visible-light-induced copper-catalyzed arylation of C

• photoinduced copper-catalyzed α-C(sp3)–H cyclization of aliphatic alcohols with o-aminobenzamide. However, the aliphatic alcohols were limited to methanol and ethanol. In this transformation, α-C(sp3)–H of MeOH/EtOH undergoes a hydrogen atom transfer (HAT) process to synthesize quinazolinones involving ligand

Direct C(sp³)–H allylation of 2-alkylpyridines with Morita–Baylis–Hillman carbonates via a tandem nucleophilic substitution/aza-Cope rearrangement

• Siyu Wang,
• Lianyou Zheng,
• Shutao Wang,
• Shulin Ning,
• Zhuoqi Zhang and
• Jinbao Xiang

Beilstein J. Org. Chem. 2021, 17, 2505–2510, doi:10.3762/bjoc.17.167

• . However, these reactions were mainly suitable to strong nucleophiles such as malonates, amines, or alcohols etc. [20][21][22][23]. The allylic substitution reactions using some weak nucleophiles, such as alkyl aza-arenes, were very limited [24][25][26][27][28][29]. In 2014, Rios and coworkers developed a

Targeting active site residues and structural anchoring positions in terpene synthases

• Anwei Hou and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 2441–2449, doi:10.3762/bjoc.17.161

• incorporated by its nucleophilic attack at a cationic intermediate, leading to terpene alcohols [5][6] or sometimes ethers [7][8]. Substrate ionisation by TPSs is achieved through binding of the diphosphate portion to a trinuclear Mg2+ cluster in the active site that is itself bound to two highly conserved