A new approach to ferrocene derived alkenes via copper-catalyzed olefination

• Vasily M. Muzalevskiy,
• Aleksei V. Shastin,
• Alexandra D. Demidovich,
• Namiq G. Shikhaliev,
• Abel M. Magerramov,
• Victor N. Khrustalev,
• Rustem D. Rakhimov,
• Sergey Z. Vatsadze and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

• methods for the preparation of ethynylferrocenes [24][25][26][27][28][29]. In most cases, the key reagents for the synthesis of ethynylferrocene are the corresponding mono- and dihalogenvinylferrocene derivatives. These compounds are generally prepared using a variation of the Wittig reaction (the Corey

Preparation of conjugated dienoates with Bestmann ylide: Towards the synthesis of zampanolide and dactylolide using a facile linchpin approach

• Jingjing Wang,
• Samuel Z. Y. Ting and
• Joanne E. Harvey

Beilstein J. Org. Chem. 2015, 11, 1815–1822, doi:10.3762/bjoc.11.197

• , if the α-phosphoranylidene ester or amide is formed in the presence of an aldehyde, ketone or ester, an additional in situ Wittig reaction can occur [12][13][14][15][16][17][18]. In this way, amides, esters and thioesters can be obtained through three-component couplings [14][16]. Intramolecular

• and Michael addition, followed by a Wittig reaction [19][20]. Although the utility of the Bestmann ylide in the synthesis of acyclic α,β-unsaturated esters and dienamides has already been reported [11][13][16], its application to the synthesis of α,β,γ,δ-unsaturated esters (i.e., dienoates) remains

• uncharted. In this paper, a three-component reaction between α,β-unsaturated aldehydes, alcohols and the Bestmann ylide is described. The scope of this esterification–Wittig reaction sequence in the synthesis of α,β,γ,δ-unsaturated esters is studied, and the method is applied in an approach towards the

Cross-metathesis reaction of α- and β-vinyl C-glycosides with alkenes

• Ivan Šnajdr,
• Kamil Parkan,
• Filip Hessler and
• Martin Kotora

Beilstein J. Org. Chem. 2015, 11, 1392–1397, doi:10.3762/bjoc.11.150

• vinyl β-C-deoxyribofuranoside was based on transformation of 6-O-tert-butyldiphenylsilyl-3,5-dideoxy-5-iodo-L-lyxo-hexofuranose [14]. A reaction sequence relying on Horner–Wadsworth–Emmons/ring closure–halogenation/Ramberg–Bäcklund/Wittig reaction gave rise to the equimolar mixture of styryl α- and β-C

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

Direct access to pyrido/pyrrolo[2,1-b]quinazolin-9(1H)-ones through silver-mediated intramolecular alkyne hydroamination reactions

• Hengshuai Wang,
• Shengchao Jiao,
• Kerong Chen,
• Xu Zhang,
• Linxiang Zhao,
• Dan Liu,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 416–424, doi:10.3762/bjoc.11.47

• -insertion reaction [7], the cycloaddition of anthranilic acid iminoketene to a methyl butyrolactam through a sulfinamide anhydride intermediate [9], the intramolecular aza-Wittig reaction with an azide substrate [10], and the cycloaddition of anthranilamide [11]. For the synthesis of vasicinone (5

Attempts to prepare an all-carbon indigoid system

• Şeref Yildizhan,
• Henning Hopf and
• Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 363–372, doi:10.3762/bjoc.11.42

• , and then oxidizing the presumably resulting carbanion to 21 (a known compound [19]) with Cu(OTf)2, which gave cleaner results than the chloride employed previously. Unfortunately, all efforts to convert 21 into 4 failed. Thus neither the Wittig reaction of 21 (MeP(Ph)3Br/n-BuLi, THF) nor its treatment

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• adopt a Z-configuration. Accordingly, the products of type 2 are formed in high selectivity in terms of regio- and diastereomeric control. The starting materials of type 1 were generated from the aromatic aldehydes and allyltriphenylphosphonium bromide in a Wittig reaction following a known protocol [53

Indium-mediated allylation in carbohydrate synthesis: A short and efficient approach towards higher 2-acetamido-2-deoxy sugars

• Christopher Albler,
• Ralph Hollaus,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2014, 10, 2230–2234, doi:10.3762/bjoc.10.231

• decomposition of these labile compounds. Conversion of the carbonyl moiety to an acetal group followed by treatment with azide nucleophiles also failed to yield any desired products. Therefore we decided to mask the aldehyde as an olefin. A Wittig reaction with methyl (triphenylphosphoranylidene)acetate (Ph3P

Photochemical approach to functionalized benzobicyclo[3.2.1]octene structures via fused oxazoline derivatives from 4- and 5-(o-vinylstyryl)oxazoles

• Ivana Šagud,
• Simona Božić,
• Željko Marinić and
• Marija Šindler-Kulyk

Beilstein J. Org. Chem. 2014, 10, 2222–2229, doi:10.3762/bjoc.10.230

• isocyanide (TosMIC) [38][39]. For the preparation of 5-(2-vinylstyryl)oxazole (2) by this method 3-(2-vinylphenyl)acrylaldehyde (6) was needed. This new o-substituted phenylacrylaldehyde 6 was prepared using (formylmethylene)triphenylphosphorane by a Wittig reaction from o-vinylbenzaldehyde (5). The yield of

Palladium-catalysed cyclisation of alkenols: Synthesis of oxaheterocycles as core intermediates of natural compounds

• Miroslav Palík,
• Jozef Kožíšek,
• Peter Koóš and
• Tibor Gracza

Beilstein J. Org. Chem. 2014, 10, 2077–2086, doi:10.3762/bjoc.10.216

• –Wadsworth–Emmons olefination of aldehyde 15 furnished the corresponding separable mixture of Z and E alkenes 16 and 17. In the case of utilising stabilised phosphorane ylides, the Wittig reaction provided only Z alkenes 18 and 19. Following acidic hydrolysis provided α-O-benzyl substrates 20–23 in good

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

• ]. Kishi and co-workers adopted a convergent approach to fumonisin B2, with the molecule being cleaved into three main fragments 103–105 [45][46]. The connection of 103 and 104 under formation of the fumonisin backbone would employ a Wittig reaction, followed by attachment of two molecules of

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• group has developed the synthesis of D-glucopyranose-derived counterparts of compounds 25 and 26 [73]. The formation of an intermediate imine from a sugar azide and an aldehyde by Staudinger/aza-Wittig reaction was the key step of the synthesis. 2. The Kabachnik–Fields reaction The Kabachnik–Fields

Streptopyridines, volatile pyridine alkaloids produced by Streptomyces sp. FORM5

• Ulrike Groenhagen,
• Michael Maczka,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2014, 10, 1421–1432, doi:10.3762/bjoc.10.146

• synthesized by Wittig reaction using different conditions (Scheme 1). A Wittig–Schlosser reaction [15] starting from a commercially available 5:1 E/Z-mixture of 1-bromobut-2-ene (17) led to preferentially (1E)-configured products. After conversion of 17 into the respective Wittig salt 18 and reaction with 2

• ]+ (17), 146 (29), 133 (11), 132 (100), 119 (17), 118 (30), 117 (47), 106 (25), 93 (77), 79 (17), 78 /14), 65 (18), 51 (13), 39 (19); HREIMS m/z: calcd for C10H13N, 147.1048; found, 147.1054; GC (BPX-5) I = 1208. The synthesis of compounds 9 and 12 was achieved by Wittig reaction starting with the

• )pyridine (streptopyridine A, 9), c) 2-((1E,3E)-penta-1,3-dien-1-yl)pyridine (streptopyridine B, 12). Total ion chromatograms of the product mixtures of isomers 9–12 synthesized under E-selective (a) and Z-selective Wittig reaction conditions (b). Structures of piperidine derivatives 20–26. a) Mass spectrum

Amino acid motifs in natural products: synthesis of O-acylated derivatives of (2S,3S)-3-hydroxyleucine

• Oliver Ries,
• Martin Büschleb,
• Markus Granitzka,
• Dietmar Stalke and
• Christian Ducho

Beilstein J. Org. Chem. 2014, 10, 1135–1142, doi:10.3762/bjoc.10.113

• investigated, but resulted in a moderate yield of 32% only (reaction not displayed). One-pot Swern oxidation to the corresponding aldehyde and subsequent Wittig reaction with stabilized Wittig reagent 32 led to α,β-unsaturated ester 33 in 85% yield. After simultaneous reduction of the double bond and cleavage

Structure elucidation of female-specific volatiles released by the parasitoid wasp Trichogramma turkestanica (Hymenoptera: Trichogrammatidae)

• Armin Tröger,
• Teris A. van Beek,
• Martinus E. Huigens,
• Isabel M. M. S. Silva,
• Maarten A. Posthumus and
• Wittko Francke

Beilstein J. Org. Chem. 2014, 10, 767–773, doi:10.3762/bjoc.10.72

• position 2 underwent ca. 6% epimerization to yield 7 as a mixture of 4 stereoisomers. The synthesis of 2,6,8,12-tetramethyltrideca-2,4-diene (8) was completed by Wittig reaction using (3-methylbut-2-en-1-yl)triphenylphosphonium bromide [15]. As expected, the obtained mixture of all possible stereoisomers

• , followed by oxidation, yielded the aldehyde 10, which was chain elongated by Wittig reaction with [(2E)-1-methylbut-2-en-1-yl]triphenylphosphonium bromide [17] to afford the protected dienol 11 as a mixture of 4 racemates. This was due to partial epimerization at position 2 of the aldehyde 10 and the less

• corresponding deoxygenation steps) would produce the carbon skeleton of a 4,6,8,10-tetramethyltrideca-2,4-diene (15). Thus, from a biosynthetic point of view, the structure would be reasonable and follow established principles. To test the validity of our assumption, we transformed 13 into 15 by Wittig reaction

Asymmetric total synthesis of a putative sex pheromone component from the parasitoid wasp Trichogramma turkestanica

• Danny Geerdink,
• Jeffrey Buter,
• Teris A. van Beek and
• Adriaan J. Minnaard

Beilstein J. Org. Chem. 2014, 10, 761–766, doi:10.3762/bjoc.10.71

• the reduction of 13 with DIBALH is a clean reaction, affording essentially pure 2 after work-up, the preparation of pure 13 was highly desirable. A stepwise olefination approach was therefore considered. Wittig reaction of aldehyde 11 with phosphorane 14 to give 15 was carried out first (Scheme 4) [27

• account for the observed 1H NMR signals. As the Wittig reaction of 11 did afford 15, although with the simultaneous formation of an inseparable side-product, we were curious to see how the analogous Horner–Wadsworth–Emmons olefination towards 15 would perform. Thus, aldehyde 11 was freshly prepared and

• intermediate, leading to a mixture of double bond isomers. The impurity previously observed as a result of the Wittig reaction was not present. In addition, the E- and Z-isomers could be separated using column chromatography affording pure E-15 in 45% yield. Reduction of 15 was achieved using DIBALH, affording

Synthesis of (2S,3R)-3-amino-2-hydroxydecanoic acid and its enantiomer: a non-proteinogenic amino acid segment of the linear pentapeptide microginin

• Rajendra S. Rohokale and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2014, 10, 667–671, doi:10.3762/bjoc.10.59

• -pentodialdo-1,4-furanose (3b) which was obtained from D-glucose in good yield as reported earlier [33]. Thus, the Wittig reaction of 3b followed by hydrogenation (10% Pd/C) gave 4-heptyl-D-threose derivative 5b (Scheme 3). Hydrolysis of 1,2-O-isopropylidene (TFA:H2O) followed by oxidative cleavage of the

Synthesis of complex intermediates for the study of a dehydratase from borrelidin biosynthesis

• Frank Hahn,
• Nadine Kandziora,
• Steffen Friedrich and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 634–640, doi:10.3762/bjoc.10.55

• . Synthesis of reference compounds We exploited a Wittig reaction with a suitable stabilized phosphorane for the synthesis of (E,E)-diene 6a (Scheme 4). The Wittig compound 24 was obtained in two steps from 2-bromopropionic acid following synthetic procedures described for its acetic acid analogue and the

• % yield by a Wittig reaction with stabilized phosphorane 26. The Z-isomer 10b was synthesized by Still–Gennari olefination using phosphonate 27 in 47% yield. The yield for the deprotection step was satisfying (61% for 7a and 57% for 7b) in both cases, indicating that both isomers are configurationally

Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine

• Fei Wang,
• Lingchun Li,
• Chuanfa Ni and
• Jinbo Hu

Beilstein J. Org. Chem. 2014, 10, 344–351, doi:10.3762/bjoc.10.32

• . Conclusion: Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective. Keywords: (chlorodifluoromethyl)trimethylsilane; difluorocarbene; gem-difluoroolefin; organo-fluorine; Wittig reaction; ylide

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• elusive cis-divinylcyclopropane (9) was characterized ten years later by Brown and coworkers [3] using a low temperature and very short-timed Wittig reaction between cis-vinylcarbaldehyde 11 and methylenetriphenylphoshorane. This review summarizes the recent synthetic applications of the

• rearrangement was followed by MOM-cleavage. Oxidation furnished an intermediate aldehyde, followed by Wacker oxidation and the Anders–Gaßner variant [106][107][108][109] of the Wittig reaction to furnish 5-epi-vibsanin E (115). Echavarren and coworkers [110] used a DVCPR to target the sesquiterpenoid

• reaction of dihydrooxepine 325 (see Scheme 38) to access vinylcyclopropane carbaldehyde 326, which was in situ converted into the corresponding imine 327 using an aza-Wittig reaction. Subsequent vinylcyclopropane carbimine–dihydroazepine rearrangement furnished cyclic 328 in excellent yield. Conclusion The

Total synthesis of the endogenous inflammation resolving lipid resolvin D2 using a common lynchpin

• John Li,
• May May Leong,
• Alastair Stewart and
• Mark A. Rizzacasa

Beilstein J. Org. Chem. 2013, 9, 2762–2766, doi:10.3762/bjoc.9.310

• Abstract The total synthesis of the endogenous inflammation resolving eicosanoid resolvin D2 (1) is described. The key steps involved a Wittig reaction between aldehyde 5 and the ylide derived from phosphonium salt 6 to give enyne 17 and condensation of the same ylide with aldehyde 7 to afford enyne 11

• ; resolvin D2; Sonogashira coupling; total synthesis; Wittig reaction; Introduction The resolution of inflammation is a tightly governed active process effectively mediated by a range of bioactive polyunsaturated fatty acids, peptides and proteins. In 2002, a new family of endogenously generated lipid

• using the common linchpin phosphorus ylide derived from phosphonium salt 6 [21][22] and each of the homochiral aldehydes 5 and 7 [9]. Synthesis of vinyl iodide 4 The synthesis of fragment 4 began with the production of the aldehyde 7 as shown in Scheme 2. A Wittig reaction between hemiacetal 8 [23] and

Multigramme synthesis and asymmetric dihydroxylation of a 4-fluorobut-2E-enoate

• James A. B. Laurenson,
• John A. Parkinson,
• Jonathan M. Percy,
• Giuseppe Rinaudo and
• Ricard Roig

Beilstein J. Org. Chem. 2013, 9, 2660–2668, doi:10.3762/bjoc.9.301

• literature (Scheme 3); silver mediated fluorination of butenoyl bromide 15 is known [14] delivering 16 in moderate yield but via a slow and expensive reaction. Wittig reaction, following in situ reduction of ethyl fluoroacetate (17) has been reported [15], while Purrington [16] prepared 19 by direct

• -chromophoric syn-diol products. Educt elaboration was achieved via cyclic sulfate methodology, leading to the stereocomplementary anti-diols, and via acetal protection, ester reduction and one-pot oxidation/Wittig reaction, re-connecting this study to the published route to 6-deoxy-6-fluorohexoses

Garner’s aldehyde as a versatile intermediate in the synthesis of enantiopure natural products

• Mikko Passiniemi and
• Ari M.P. Koskinen

Beilstein J. Org. Chem. 2013, 9, 2641–2659, doi:10.3762/bjoc.9.300

• , e.g., triphenylphospine oxide. As with the Wittig reaction, the HWE reaction can also promote the epimerization of the α-proton (pKa of triethoxyphosphonoacetate in DMSO is 18.6) [109]. We have experienced this tendency especially with α-amino ketophosphonates [110], but there is also evidence that

One-pot sequential synthesis of isocyanates and urea derivatives via a microwave-assisted Staudinger–aza-Wittig reaction

• Diego Carnaroglio,
• Katia Martina,
• Giovanni Palmisano,
• Andrea Penoni,
• Claudia Domini and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2013, 9, 2378–2386, doi:10.3762/bjoc.9.274

• halides and primary or secondary amines has been developed. The synthetic pathway combines nucleophilic substitutions and a Staudinger–aza-Wittig reaction in the presence of polymer-bound diphenylphosphine under 14 bar of CO2 pressure and has been performed in a one-pot two-step process. The protocol has

• : isocyanates; microwave-assisted reaction; one-pot reaction; tandem Staudinger–aza-Wittig reaction; urea derivatives; Introduction The industrial and commercial impact of isocyanates (R–NCO) is steadily growing. In particular, the polyurethane output has undergone yearly increases of 5% over the last decade

• volatile, solid and supported reagents. In summary, we herein report an optimized protocol for a MW-assisted Staudinger–aza-Wittig reaction with polymer-bound diphenylphosphine (PS-PPh2) in a CO2 atmosphere. The study also aimed to prepare a series of symmetric and asymmetric alkyl/aryl urea derivatives in

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• intramolecular addition–elimination reaction. In the presence of the aldehyde 154, 153 underwent a Horner–Wittig reaction to generate 155 as a 1:2.3 mixture of E- and Z-isomers. Treatment of 155 with boron trichloride not only liberated the phenol but also isomerized the E-double bond to the Z-isomer. Finally, a

• starting materials, via a Staudinger–aza-Wittig reaction gave amine 237 as a mixture of four diastereoisomers. Conversion into 4-oxido-isoquinolinium betaine 238 could be achieved by an acid-catalyzed methanol extrusion and isomerization. Betaine 238 served as the substrate for the following 1,3-aza