Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• between the sulfur and an ester oxygen. This phenomenon was first described in supramolecular structures by Gleiter [59] and later also used to explain the outcome of organocatalytic reactions [60]. The pure stereoisomers of 42 were isolated by preparative HPLC, for which the best separation was achieved

Direct synthesis of anomeric tetrazolyl iminosugars from sugar-derived lactams

• Michał M. Więcław and
• Bartłomiej Furman

Beilstein J. Org. Chem. 2021, 17, 115–123, doi:10.3762/bjoc.17.12

• ones in this work – fused iminosugar-tetrazoles – which have shown inhibition properties against bovine liver α-ᴅ-glucuronidase and human β-ʟ-iduronidase [29]. Moreover, there are numerous reports of the organocatalytic activity of chiral aminotriazoles and aminotetrazoles in number of reactions, such

• , potentially biologically active and organocatalytic compounds. Experimental Experimental procedures and other data are available in Supporting Information File 1. Key concepts behind the goal of this work [34]. ORTEP structures of compounds 3a and 3e obtained by X-ray analysis. Hydrogen atoms and benzyl

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• produced (−)-inthomycin C ((−)-3) in 80% yield with high enantiopurity (Scheme 7). In 2012, Hatakeyama and co-workers reported a unified strategy for the asymmetric total syntheses of inthomycin A ((+)-1), inthomycin B ((+)-2), and inthomycin C ((−)-3), starting with an organocatalytic asymmetric [2 + 2

• produce 2-methyl-5-bromodienoic amide 92 stereoselectively in 73% yield over three steps. Stille cross-coupling of 92 with vinylstannane 24 followed by DIBAL-H reduction produced aldehyde 71, which then underwent an organocatalytic Mukaiyama aldol reaction with silylketene acetal 53 to produce racemic (E

Asymmetric Mannich reactions of (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines with yne nucleophiles

• Ziyi Li,
• Li Wang,
• Yunqi Huang,
• Haibo Mei,
• Hiroyuki Konno,
• Hiroki Moriwaki,
• Vadim A. Soloshonok and
• Jianlin Han

Beilstein J. Org. Chem. 2020, 16, 2671–2678, doi:10.3762/bjoc.16.217

• trifluoromethylpropargylamine is of general research interest [28][29][30][31][32]. The asymmetric Ru/(R)-CPA-catalyzed chemoselectivie biomimetic reduction [33] and the organocatalytic transfer hydrogenation [34] of fluorinated alkynylketimines have been developed for the synthesis of fluorinated propargylamines in good

Stereoselective Biginelli-like reaction catalyzed by a chiral phosphoric acid bearing two hydroxy groups

• Xiaoyun Hu,
• Jianxin Guo,
• Cui Wang,
• Rui Zhang and
• Victor Borovkov

Beilstein J. Org. Chem. 2020, 16, 1875–1880, doi:10.3762/bjoc.16.155

• described the efficient asymmetric Biginelli reaction with a chiral ytterbium catalyst to provide excellent enantioselectivities up to >99% ee [12]. Later, Gong reported the first organocatalytic Biginelli reaction using 1,1'-bi-2-naphthol (BINOL) derived chiral phosphoric acids as catalysts, furnishing the

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

Fluorohydration of alkynes via I(I)/I(III) catalysis

• Jessica Neufeld,
• Constantin G. Daniliuc and
• Ryan Gilmour

Beilstein J. Org. Chem. 2020, 16, 1627–1635, doi:10.3762/bjoc.16.135

• -based fluorination, a complementary organocatalytic variant [52], based on an I(I)/I(III) catalysis platform was explored (Figure 1C). It was envisaged that the in situ generation of p-TolIF2 via oxidation of p-TolI with Selectfluor® in the presence of an amine/HF complex might enable the title

• substrate specificity in small-molecule catalysis. It is envisaged that this organocatalytic variant of the venerable Kucherov reaction will find application in contemporary organofluorine chemistry [61] and contributes to the current interest in alkyne functionalisation via I(I)/I(III) catalysis [62][63

NHC-catalyzed enantioselective synthesis of β-trifluoromethyl-β-hydroxyamides

• Alyn T. Davies,
• Mark D. Greenhalgh,
• Alexandra M. Z. Slawin and
• Andrew D. Smith

Beilstein J. Org. Chem. 2020, 16, 1572–1578, doi:10.3762/bjoc.16.129

• practical methodologies capable of the enantioselective incorporation of the trifluoromethyl unit into organic molecules has been developed widely [10][11][12], with a series of elegant organocatalytic strategies utilized toward these aims [13]. One general strategy for the organocatalytic construction of

• with amine nucleophiles allowed access to β-trifluoromethyl-β-hydroxyamides in moderate to good yield as single diastereoisomers in excellent er following purification [61]. Organocatalytic enantioselective aldol approaches using trifluoroacetophenone derivatives. NHC-catalyzed approaches to β-lactones

An overview on disulfide-catalyzed and -cocatalyzed photoreactions

• Yeersen Patehebieke

Beilstein J. Org. Chem. 2020, 16, 1418–1435, doi:10.3762/bjoc.16.118

• hydrodecarboxylation product 55. Nicewicz and co-workers also reported the decarboxylation of carboxylic acids and malonic acid derivatives catalyzed by an acridinium photoredox catalyst (Mes–Acr–Ph) and PhSSPh in 2015 (Scheme 20) [27]. This direct method of the organocatalytic decarboxylation of carboxylic acids to

Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

• Péter Bagi,
• Réka Herbay,
• Nikolett Péczka,
• Zoltán Mucsi,
• István Timári and
• György Keglevich

Beilstein J. Org. Chem. 2020, 16, 818–832, doi:10.3762/bjoc.16.75

• the 2-phospholene derivatives is beneficial for having enhanced organocatalytic activity, in a few instances [47]. The McCormack cycloaddition is a key reaction for the preparation of the five-membered P-heterocyclic scaffold, as both the 2- or 3-phospholene core can be prepared depending on the

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• in the pyrrolidine ring catalyzed by RhCl3·H2O, followed by debenzylation, amidation, and aminal generation using the Stille protocol [77]. (–)‐Clavukerin A and related sesquiterpenes Applying original organocatalytic/metal-catalyzed tactics, Metz et al. [78] reported a tandem dienyne RCM for the

• enantiopure trienyne or diene–diyne metathesis precursors were readily obtained from (S)-citronellal by a highly diastereoselective organocatalytic Michael addition. Erogorgiaene An exceptionally stereoselective synthesis of erogorgiaene (12) (95% E-selectivity) was reported by Hoveyda et al. [80]. They

Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst

• Abhijit Paul,
• Debnath Chatterjee,
• Srirupa Banerjee and
• Somnath Yadav

Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16

• purification [17][18]. As an example for the second category, Jiao and co-workers developed an organocatalytic C3–H alkenylation of indoles by the reaction of indoles with α,β-unsaturated aldehydes in presence of morpholin-4-ium trifluoroacetate as a catalyst and a stoichiometric amount of DDQ to achieve

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• their review article [72]. In this section, we will be presenting a concise description of the use of organocatalysts as chiral inductors in electroorganic synthesis. In 2008, Page, Marken and their group reported a method for electricity-driven asymmetric organocatalytic epoxidation. The percarbonate

1,5-Phosphonium betaines from N-triflylpropiolamides, triphenylphosphane, and active methylene compounds

• Vito A. Fiore,
• Chiara Freisler and
• Gerhard Maas

Beilstein J. Org. Chem. 2019, 15, 2603–2611, doi:10.3762/bjoc.15.253

• leading to butenolides occurs easily [17]. In contrast to acetylenic esters and ketones, acetylenic carboxamides have rarely been exposed to nucleophilic phosphanes in organocatalytic or stoichiometric reactions. Recently, we have reported on the synthesis and reactivity of N-triflylpropiolamides 1

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• introducing a variety of chiral building blocks in the 1,2,3-triazolium macrocycles valuable insight may be provided into the enantioselective recognition and transformation of guest molecules. In the past decades, organocatalytic routes have emerged as an effective and ecofriendly approach towards the

An overview of the cycloaddition chemistry of fulvenes and emerging applications

• Ellen Swan,
• Kirsten Platts and
• Anton Blencowe

Beilstein J. Org. Chem. 2019, 15, 2113–2132, doi:10.3762/bjoc.15.209

• organocatalytic, enantioselective intramolecular cycloaddition reaction was reported by Hayashi et al. for the synthesis of various tricyclopentanoids from pentafulvenes with δ-formyl groups tethered to the exocyclic C6 position via structurally distinct spacers [85]. The intramolecular [6 + 2] cycloaddition was

α-Photooxygenation of chiral aldehydes with singlet oxygen

• Dominika J. Walaszek,
• Magdalena Jawiczuk,
• Jakub Durka,
• Olga Drapała and
• Dorota Gryko

Beilstein J. Org. Chem. 2019, 15, 2076–2084, doi:10.3762/bjoc.15.205

• University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland 10.3762/bjoc.15.205 Abstract Organocatalytic α-oxygenation of chiral aldehydes with photochemically generated singlet oxygen allows synthesizing chiral 3-substituted 1,2-diols. Stereochemical results indicate that the reaction in the presence

• -hydroxylation of aldehydes [14][15]. Recently, we have reported that organocatalytic photooxygenation of aldehydes affords the desired diols (after in situ reduction) in decent yield with either (R)- or (S)-selectivity depending on a catalysts used [14]. In the presence of prolinamides the (R)-enantiomer

• er for enantioenriched substrate 1 thus indicating that the organocatalytic photooxygenation of aldehydes with singlet oxygen is highly diastereoselective. In the case, when two chiral compounds participate in a given reaction, they, according to Masamune, may be considered as matching or mismatching

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

• Piyali Sarkar,
• Sayan Sarkar and
• Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

• Piyali Sarkar Sayan Sarkar Pradyut Ghosh School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S.C Mullick Road, Kolkata-700032, India 10.3762/bjoc.15.152 Abstract A heteroditopic macrocycle is reported as an efficient organocatalytic nanoreactor for the

• environmentally benign solvent water has been used [11]. Organocatalytic nanoreactors have emerged as an exciting area for novel organic syntheses, offering environmentally friendlier processes [13][14][15][16][17][18]. The distinct nanospace around the substrates, use of green solvents and catalyst recycling

• , makes them highly valuable in view of sustainable chemical applications. Thus, the development of organocatalytic nanoreactors with new features is indeed important to address greener organic syntheses. On the other hand, the rational design of heterotopic macrocycles has attracted intense interest as

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• line. A very recent example of a highly diastereoselective Ugi-type MCR was reported by Rivera, Paixão and co-workers using a steroidal isocyanide [31]. As shown in Scheme 9, the procedure comprised the organocatalytic asymmetric synthesis of the chiral bifunctional substrate 30 bearing an masked

• organocatalytic multicomponent approaches [32] not only the chiral steroidal isocyanide but also the bifunctional component 30, used in enantiomerically enriched form, plays a crucial role in the high stereoselection. The mechanistic insights of this class of MCR were disclosed in the original publication [31

• ]. In short, the organocatalytic conjugated addition of benzoylacetonitrile to cinnamaldehyde generates the hemiacetal 30, which next initiates the multicomponent sequence upon condensation with the aniline and formation of the imine, eventually occurring as a stable cyclic aminal. The attack of the

Ugi reaction-derived prolyl peptide catalysts grafted on the renewable polymer polyfurfuryl alcohol for applications in heterogeneous enamine catalysis

• Alexander F. de la Torre,
• Gabriel S. Scatena,
• Oscar Valdés,
• Daniel G. Rivera and
• Márcio W. Paixão

Beilstein J. Org. Chem. 2019, 15, 1210–1216, doi:10.3762/bjoc.15.118

• polyfurfuryl alcohol-supported catalysts for applications in heterogeneous enamine catalysis. The utilization of the polymer-supported catalysts in both batch and continuous-flow organocatalytic procedures proved moderate catalytic efficacy and enantioselectivity, but excellent diastereoselectivity in the

• employ a three-component, diastereoselective variant of the Ugi reaction for the synthesis of a prolyl pseudo-peptide catalyst, which proved effective in an organocatalytic conjugate addition reaction [6]. Later, our groups developed an Ugi reaction-based multicomponent approach enabling the structure

• diversification of prolyl pseudo-peptide catalysts [7], which also proved great efficacy in organocatalytic asymmetric Michael reactions. As extension of this concept to the field of immobilized organocatalysts, we reported the use of the multicomponent approach for the synthesis of silica-grafted peptide

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

• mechanochemical ball milling. The organocatalytic polymerization of trimethylene carbonate to form aliphatic polycarbonates was found to be more efficient when using a mechanical ball-milling reaction than a solution polymerization (Scheme 1). The detailed findings are disclosed in this article. Results and

Catalytic asymmetric oxo-Diels–Alder reactions with chiral atropisomeric biphenyl diols

• Chi-Tung Yeung,
• Wesley Ting Kwok Chan,
• Wai-Sum Lo,
• Ga-Lai Law and
• Wing-Tak Wong

Beilstein J. Org. Chem. 2019, 15, 955–962, doi:10.3762/bjoc.15.92

• acid catalysts for over three decades [15][16][17][18][19][20][21][22][23][24][25][26]. Comparatively, interest in the utilization of metal-free organocatalytic oxo-DA reactions began to grow only after Rawal’s group reported a ground-breaking contribution in using a diol molecule, TADDOL, as a

An efficient synthesis of the guaiane sesquiterpene (−)-isoguaiene by domino metathesis

• Yuzhou Wang,
• Ahmed F. Darweesh,
• Patrick Zimdars and
• Peter Metz

Beilstein J. Org. Chem. 2019, 15, 858–862, doi:10.3762/bjoc.15.83

• (−)-Isoguaiene was prepared from (S)-citronellal in only 9–10 steps with good overall yields. Either a trienyne or a dienediyne metathesis and highly diastereoselective organocatalytic Michael additions of aldehydes derived from (S)-citronellal served as the key transformations. Keywords: domino reactions

• were interested in developing an efficient synthetic access to 1 using a combined organocatalytic/metal-catalyzed strategy related to the one applied to the preparation of 2 [7][8]. Results and Discussion As illustrated in Scheme 1, two alternative routes were retrosynthetically devised, both of which

• feature a domino metathesis event and an organocatalytic Michael addition as the key steps. In closer analogy to our improved synthesis of clavukerin A (2) [8], a relay metathesis [9] of trienyne 3 was expected to lead to the hydroazulene 1 selectively. Trienyne 3 was envisioned to result from a

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• recycle catalysts. However, only a limited number of organocatalytic moieties and functional groups have been attached to CD scaffolds so far. Cinchona alkaloids are commonly used to catalyze a wide range of enantioselective reactions. Thus, in this study, we report the preparation of new α- and β-CD

• well-explored strategy [2] which can be used to prepare various types of CD derivatives. Several examples of modified-CD derivatives with a catalytic nucleophilic center have been reported in the area of organocatalytic asymmetric reactions [11]. Initially, Kanagaraj et al. [16] used per-6-amino-β-CD

• potential of asymmetric organocatalytic reactions using CD derivatives. However, a wide range of catalytic groups, especially cinchona alkaloids (Figure 2), have been used in organocatalysis with excellent results. These naturally occurring compounds and their derivatives are commonly applied in various

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

• enantioenriched precursors (R)-56a and (R)-56i (Scheme 21) [61]. The addition of a cyclopropenyllithium to an aldehyde is arguably the most widely used method to access cyclopropenylcarbinols but Gevorgyan et al. disclosed an interesting organocatalytic route to cyclopropenylcarbinols possessing gem-diester