Copper-catalyzed aminooxygenation of styrenes with N-fluorobenzenesulfonimide and N-hydroxyphthalimide derivatives

• Yan Li,
• Xue Zhou,
• Guangfan Zheng and
• Qian Zhang

Beilstein J. Org. Chem. 2015, 11, 2721–2726, doi:10.3762/bjoc.11.293

• aminooxygenation reaction of alkenes with phthalimide and (diacetoxyiodo)benzene through cis-aminopalladation and SN2 C–O bond formation [34]. In 2013, Zhu and co-workers described an n-Bu4NI-catalyzed aminooxygenation of inactive alkenes with benzotriazole and water which underwent a nitrogen-centred radical

Recent advances in copper-catalyzed asymmetric coupling reactions

• Fengtao Zhou and
• Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

• different products: the SN2-product or the SN2’-product (Scheme 24). Usually, SN2’ regioselective allylic substitutions, which create a new stereogenic center, are more valuable. Methods that allow the SN2’ regioselective C–C bond formation have been extensively studied over the past years. In contrast to

• other metals (Pd, Mo, and Ir), copper-catalyzed allylic substitution reactions allow the use of nonstabilized nucleophiles including organomagnesium, organoaluminum, organozinc and organoborane reagents. Moreover, copper-catalyzed allylic substitution reactions usually proceed with high SN2

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• nine-membered carbocyclic ring. Treatment of this intermediate with potassium tert-butoxide led to the cleavage of the 2-cyanoethylsulfide moiety and the generation of a thiolate anion, which underwent SN2 displacement of the primary mesylate, affording the 13-membered lactam 56. The stage was now set

Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

• Bijay Shrestha and
• Ramesh Giri

Beilstein J. Org. Chem. 2015, 11, 2400–2407, doi:10.3762/bjoc.11.261

• -catalyzed couplings of organometallic reagents with alkyl electrophiles have previously been shown to proceed via an SN2 process [34][35]. Therefore, we believe that a similar mechanistic scenario can also be envisioned in the current Cu-catalyzed cross-coupling of triarylaluminum reagents with primary

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

• Mohamed Ramadan El Sayed Aly,
• Hosam Ali Saad and
• Shams Hashim Abdel-Hafez

Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208

• with CBr4/PPh3 to afford 3α-bromocholest-5-ene 2 due to inversion of the configuration at the C-3 carbon (Scheme 1). The O–Hstr band of 1 disappeared upon this step. An SN2 substitution of the bromine atom of compound 2 with the N3 group was ensued by refluxing with NaN3 in dry DMF to afford 3β

Synthesis of a tricyclic lactam via Beckmann rearrangement and ring-rearrangement metathesis as key steps

• Sambasivarao Kotha,
• Ongolu Ravikumar and
• Jadab Majhi

Beilstein J. Org. Chem. 2015, 11, 1503–1508, doi:10.3762/bjoc.11.163

• -caprolactam from cyclohexanone oxime involving the BR. The activation energy for the BR is almost the same as that of the nucleophilic substitution at sp2 nitrogen. To synthesize various aza-arenes and cyclic imines, such as quinolines, aza-spiro compounds and dihydropyrroles, the intramolecular SN2-type

Structure and conformational analysis of spiroketals from 6-O-methyl-9(E)-hydroxyiminoerythronolide A

• Ana Čikoš,
• Irena Ćaleta,
• Dinko Žiher,
• Mark B. Vine,
• Ivaylo J. Elenkov,
• Marko Dukši,
• Dubravka Gembarovski,
• Marina Ilijaš,
• Snježana Dragojević,
• Ivica Malnar and
• Sulejman Alihodžić

Beilstein J. Org. Chem. 2015, 11, 1447–1457, doi:10.3762/bjoc.11.157

• equatorial position on the tetrahydropyran ring. Prolonged acidic treatment of 2 leads either back to C1 or to its isomer C2. The latter loses a molecule of water via an intramolecular SN2’ mechanism forming the unsaturated spiroketal 3. Repeated spiroketal opening leads to the conjugated enol ether E with

Surprisingly facile CO₂ insertion into cobalt alkoxide bonds: A theoretical investigation

• Willem K. Offermans,
• Claudia Bizzarri,
• Walter Leitner and
• Thomas E. Müller

Beilstein J. Org. Chem. 2015, 11, 1340–1351, doi:10.3762/bjoc.11.144

• theoretical study, in which the initiation and propagation steps of the copolymerisation were addressed. The initiation started with the coordination of epoxide at a penta-coordinated metal–salen complex, followed by a nucleophilic, SN2-like, back-side attack on such a coordinated epoxide. The propagation

Advances in the synthesis of functionalised pyrrolotetrathiafulvalenes

• Luke J. O’Driscoll,
• Sissel S. Andersen,
• Marta V. Solano,
• Dan Bendixen,
• Morten Jensen,
• Troels Duedal,
• Jess Lycoops,
• Cornelia van der Pol,
• Rebecca E. Sørensen,
• Karina R. Larsen,
• Kenneth Myntman,
• Christian Henriksen,
• Stinne W. Hansen and
• Jan O. Jeppesen

Beilstein J. Org. Chem. 2015, 11, 1112–1122, doi:10.3762/bjoc.11.125

• convenient than the use of CsOH·H2O. N-Arylation of MPTTFs and BPTTFs N-Alkylation of MPTTFs and BPTTFs can be easily achieved using SN2 reactions between a deprotonated pyrrole and a suitably activated aliphatic species [19][28]. N-Arylation of MPTTFs and BPTTFs, which allows an annelated TTF to be

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• reaction of 5 with 4-bromoiodobenzene gave compound 6 quantitatively. The treatment of 6 with Ac2O and a catalytic amount of N,N-dimethyl-4-aminopyridine (DMAP) gave the acetyl ester 7 in 93% yield. The formation of 1,3-bis(4-bromophenyl)-1,3-diisopropylallene (8) was achieved by an SN2’-type reaction of 7

Metal-free one-pot synthesis of 2-substituted and 2,3-disubstituted morpholines from aziridines

• Hongnan Sun,
• Binbin Huang,
• Run Lin,
• Chao Yang and
• Wujiong Xia

Beilstein J. Org. Chem. 2015, 11, 524–529, doi:10.3762/bjoc.11.59

• -substituted and 2,3-disubstituted morpholines through a one-pot strategy is described. A simple and inexpensive ammonium persulfate salt enables the reaction of aziridines with halogenated alcohols to proceed via an SN2-type ring opening followed by cyclization of the resulting haloalkoxy amine. Keywords

A procedure for the preparation and isolation of nucleoside-5’-diphosphates

• Heidi J. Korhonen,
• Hannah L. Bolt and
• David R. W. Hodgson

Beilstein J. Org. Chem. 2015, 11, 469–472, doi:10.3762/bjoc.11.52

• (triphenylphosphoranylidene)ammonium] pyrophosphate (PPN pyrophosphate) was used in the SN2 displacements of the tosylate ion from 5’-tosylnucleosides to afford nucleoside-5’-diphosphates. Selective precipitation permitted the direct isolation of nucleoside-5’-diphosphates from crude reaction mixtures. Keywords: NDP

• quantities of NTP than NDP [15][16]. Nuceloside-5’-diphosphates can, however, be accessed via SN2 displacement at 5’-activated nucleosides using pyrophosphate as the nucleophile. This approach, developed by Poulter and co-workers [17], forms a cornerstone in the armoury towards the synthesis of nucleoside-5

Anionic sigmatropic-electrocyclic-Chugaev cascades: accessing 12-aryl-5-(methylthiocarbonylthio)tetracenes and a related anthra[2,3-b]thiophene

• Laurence Burroughs,
• John Ritchie,
• Mkhethwa Ngwenya,
• Dilfaraz Khan,
• William Lewis and
• Simon Woodward

Beilstein J. Org. Chem. 2015, 11, 273–279, doi:10.3762/bjoc.11.31

• rearrangement of 1a [14] or by SN2’ carbonate displacement in 1b by Pd0(PPh3)2 in Liu’s case [16]. To circumvent reversibility of these pericyclic annulation strategies Lin relied on PhSOH elimination while Liu relied on ubiquitous palladium β-hydride steps leading to tetracenes 3 and 4. We are interested in

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer

• Francesco Trotta,
• Fabrizio Caldera,
• Roberta Cavalli,
• Andrea Mele,
• Carlo Punta,
• Lucio Melone,
• Franca Castiglione,
• Barbara Rossi,
• Monica Ferro,
• Vincenza Crupi,
• Domenico Majolino,
• Valentina Venuti and
• Dominique Scalarone

Beilstein J. Org. Chem. 2014, 10, 2586–2593, doi:10.3762/bjoc.10.271

• presence of Cu2+, Fe3+, Ba2+, Cd2+, Pb2+ and Sn2+, by forming metal–organic complexes. Conversely, no precipitation occurs with Ca2+, Mg2+, Fe2+, Mn2+, Ni2+ and Ce4+, showing some selectivity towards certain metal cations and indirect evidence of polyelectrolyte behavior. A gross evaluation of the

Synthesis of phosphoramidites of isoGNA, an isomer of glycerol nucleic acid

• Keunsoo Kim,
• Venkateshwarlu Punna,
• Phaneendrasai Karri and
• Ramanarayanan Krishnamurthy

Beilstein J. Org. Chem. 2014, 10, 2131–2138, doi:10.3762/bjoc.10.220

• for the introduction of the canonical nucleobases by a SN2 displacement reaction. At this point, we chose the Mitsunobu reaction (Scheme 1), which has been widely employed [16]. The reaction with the N3-benzoyl protected thymine delivered 5 in good yield. However, the reaction with N6-benzoyladenine

• proved problematic and no product was detected. Therefore, in the adenine case, we tried a direct SN2 reaction of N6-benzoyladenine with tosyl derivative 6, which was only moderately successful (30% yield of 7). Unexpectedly, in both the thymine and adenine cases, the subsequent debenzylation reaction

• protecting group approach. We silylated 1 to afford 8 whose ketal was deprotected followed by tritylation to give the derivative 10, which is expected to be suited for the introduction of nucleobases by an SN2 reaction (Scheme 2). Once again, the Mitsunobu reaction with thymine proceeded smoothly. However

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

• -RC reaction between the α,β-unsaturated imine and the enolate, followed by an SN2 reaction. 2.14 Annulations through double-Michael additions The bisphosphine-catalyzed double-Michael addition of dinucleophiles to electron-deficient alkynes provides an efficient approach for the synthesis of

A new charge-tagged proline-based organocatalyst for mechanistic studies using electrospray mass spectrometry

• J. Alexander Willms,
• Rita Beel,
• Martin L. Schmidt,
• Christian Mundt and
• Marianne Engeser

Beilstein J. Org. Chem. 2014, 10, 2027–2037, doi:10.3762/bjoc.10.211

• ). An SN2 reaction with 5 [55] led to 8. We abandoned our initial shorter synthetic route based on a Mitsunobu reaction leading from 6 directly to 8 due to severe purification difficulties. Compound 8 could be charge-tagged to 9 using ethyl bromide. Finally, the free catalyst 1 was obtained by acidic

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

• Mahesh K. Lakshman,
• Manish K. Singh,
• Mukesh Kumar,
• Raghu Ram Chamala,
• Vijayender R. Yedulla,
• Domenick Wagner,
• Evan Leung,
• Lijia Yang,
• Asha Matin and
• Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

• mechanisms were proposed, namely reaction of the carboxylate at the phosphorus center (equivalent to pathway a in Scheme 3) or a SN2’ reaction at the N3 atom (equivalent to pathway b in Scheme 3) [34]. Experiments with [18O]-labeled benzoate indicated that conversion of carboxylic acids to the acyl HOBt

• displacement of the leaving group by attack at the N1 or by a SN2’-type of process by reaction at the N3 of the triazolyl moiety. The mechanistic analyses were conducted by a combination of 31P{1H}, [18O]-labeling, and other chemical experiments. The reaction of phenol with Bt-OTs yielded only the phenyl

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

One-pot stereoselective synthesis of α,β-differentiated diamino esters via the sequence of aminochlorination, aziridination and intermolecular S_N2 reaction

• Yiwen Xiong,
• Ping Qian,
• Chenhui Cao,
• Haibo Mei,
• Jianlin Han,
• Guigen Li and
• Yi Pan

Beilstein J. Org. Chem. 2014, 10, 1802–1807, doi:10.3762/bjoc.10.189

• directly from cinnamate esters using N,N-dichloro-p-toluenesulfonamide and benzylamine as nitrogen sources. The key transformations include a Cu-catalyzed aminohalogenation and aziridination, followed by an intermolecular SN2 nucleophilic ring opening by benzylamine. The reactions feature a wide scope of

• , the reaction could be conducted in a one-pot model, under operationally convenient conditions [36][37][38][39] through Cu-catalyzed aminohalogenation, aziridination and intermolecular SN2 nucleophilic ring opening without isolation of haloamine intermediate (Scheme 1). Results and Discussion According

• results, a proposed reaction mechanism for this one-pot reaction is illustrated in Scheme 4, which contains the sequence of aminochlorination, aziridination and followed by the SN2 nucleophilic ring-opening. The first step is the Cu-catalyzed aminochlorination reaction of methyl cinnamate 1a resulting in

Proton transfers in the Strecker reaction revealed by DFT calculations

• Shinichi Yamabe,
• Guixiang Zeng,
• Wei Guan and
• Shigeyoshi Sakaki

Beilstein J. Org. Chem. 2014, 10, 1765–1774, doi:10.3762/bjoc.10.184

• -aminopropanonitrile 8. Starting from 4, a concerted SN2-type pathway was also examined, which directly leads to the nitrile compound 8; see Scheme 6. In this pathway, the proton is transferred from the NH3+ group to the hydroxy group via a two-water-molecule bridge. At the same time, the H2O elimination and the

Orthogonal dual thiol–chloroacetyl and thiol–ene couplings for the sequential one-pot assembly of heteroglycoclusters

• Michele Fiore,
• Gour Chand Daskhan,
• Baptiste Thomas and
• Olivier Renaudet

Beilstein J. Org. Chem. 2014, 10, 1557–1563, doi:10.3762/bjoc.10.160

• alkyne–azide cycloaddition (CuAAC) [18] or SN2 reaction [19]. In addition, orthogonal chemoselective ligations were proved more attractive strategies to prepare hGCs in high yields, in part because they require less synthetic and purification steps. For example, oxime and CuAAC ligations have been used

Magnesium bis(monoperoxyphthalate) hexahydrate as mild and efficient oxidant for the synthesis of selenones

• Andrea Temperini,
• Massimo Curini,
• Ornelio Rosati and
• Lucio Minuti

Beilstein J. Org. Chem. 2014, 10, 1267–1271, doi:10.3762/bjoc.10.127

• different alkyl phenyl selenides to the corresponding selenones. Since the phenylselenonyl group is an excellent leaving group, selenone 2 readily undergoes SN2 type substitution reactions with common nucleophiles [7][8] as shown in Scheme 2. A wide range of heterocyclic compounds can be obtained by

• intermediates which readily undergo intramolecular SN2 type substitution reactions to afford a range of heterocyclic compounds (Table 2, entries 2–7) and benzeneseleninic acid. Thus, the oxidation of β-hydroxyalkyl phenyl selenide 1e gave, in tetrahydrofuran and in the presence of dipotassium hydrogen phosphate

Regioselective S_N2' Mitsunobu reaction of Morita–Baylis–Hillman alcohols: A facile and stereoselective synthesis of α-alkylidene-β-hydrazino acid derivatives

• Silong Xu,
• Jian Shang,
• Junjie Zhang and
• Yuhai Tang

Beilstein J. Org. Chem. 2014, 10, 990–995, doi:10.3762/bjoc.10.98

• Silong Xu Jian Shang Junjie Zhang Yuhai Tang Department of Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, P. R. China 10.3762/bjoc.10.98 Abstract A highly regioselective SN2' Mitsunobu reaction between Morita–Baylis–Hillman (MBH) alcohols, azodicarboxylates, and

• –Hillman; SN2' reaction; Introduction Hydrazines and their derivatives are an important class of compounds in organic chemistry. They are widely used in the fields of pesticides, polymers, dyestuff, and pharmaceutical agents [1]. They are also versatile building blocks for accessing many important

• pioneering SN2' Mitsunobu reaction of MBH alcohols with carboxylic acids [31][32], we envisioned that direct treatment of simpler MBH alcohols with azodicarboxylates and PPh3 (Mitsunobu conditions) would chemoselectively provide trisubstituted hydrazines of type 3, via a distinct SN2' Mitsunobu reaction