- One-pot oxidation/isomerization of Z-allylic alcohols with oxygen as stoichiometric oxidant
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A method for generating (E)-α,β-unsaturated aldehydes from Z-allylic alcohols or E/Z-mixtures is described. The one-pot procedure involves a Cu-catalyzed oxidation followed by an organocatalytic Z/E-isomerization with N,N-dimethylaminopyridine (DMAP).
- Koenning, Daniel,Hiller, Wolf,Christmann, Mathias
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Read Online
- Copper-free Sonogashira coupling of cyclopropyl iodides with terminal alkynes
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The substrate scope of the copper-free Sonogashira coupling has been successfully extended to cyclopropyl iodides, allowing an efficient access to a wide variety of functionalized alkynyl cyclopropanes.(Figure Presented)
- De Carne-Carnavalet, Benoit,Archambeau, Alexis,Meyer, Christophe,Cossy, Janin,Folleas, Benoit,Brayer, Jean-Louis,Demoute, Jean-Pierre
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Read Online
- Alkyne Aminopalladation/Heck and Suzuki Cascades: An Approach to Tetrasubstituted Enamines
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Alkyne aminopalladation reactions starting from tosylamides are reported. The emerging vinylic Pd species are converted either in an intramolecular Heck reaction with olefinic units or in an intermolecular Suzuki reaction by using boronic acids exhibiting broad functional group tolerance. Tetra(hetero)substituted tosylated enamines are obtained in a simple one-pot process.
- Geffers, Finn J.,Jones, Peter G.,Kurth, Florens R.,Werz, Daniel B.
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supporting information
p. 14846 - 14850
(2021/10/19)
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- Fluorinated triazole-containing sphingosine analogues. Syntheses and in vitro evaluation as SPHK inhibitors
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Sphingosine analogues with a rigid triazole moiety in the aliphatic chain and systematic modifications in the polar head and different degrees of fluorination at the terminus of the alkylic chain were synthesized from a common alkynyl aziridine key synthon. This key synthon was obtained by enantioselective organocatalyzed aziridination and it was subsequently ring opened in a regioselective manner in acidic medium. Up to 16 sphingosine analogues were prepared in a straightforward manner. The in vitro activity of the obtained products as SPHK1 and SPHK2 inhibitors was evaluated, displaying comparable activity to that of DMS.
- Escudero-Casao, Margarita,Cardona, Adrià,Beltrán-Debón, Raúl,Díaz, Yolanda,Matheu, M. Isabel,Castillón, Sergio
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supporting information
p. 7230 - 7235
(2018/10/24)
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- Sulfated tungstate as hydroxyl group activator for preparation of benzyl, including p-methoxybenzyl ethers of alcohols and phenols
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Sulfated tungstate was found to be an effective heterogeneous and reusable catalyst for hydroxy group activation–mediated preparation of benzylic ethers including p-methoxybenzylic ethers of a wide range of alcohols and phenols under mild reaction conditions.
- Katkar, Kamlesh V.,Veer, Sachin D.,Akamanchi, Krishnacharya G.
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supporting information
p. 1893 - 1901
(2016/11/25)
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- Towards the total synthesis of marineosin A: Construction of the macrocyclic pyrrole and an advanced, functionalized spiroaminal model
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Herein, we describe the enantioselective construction of the 12-membered macrocyclic pyrrole core of marineosin A in 5.1 % overall yield from (S)-propylene oxide. The route features a key Stetter reaction to install a 1,4-diketone, which is subjected to Paal-Knorr pyrrole synthesis and ring-closing metathesis to afford the macrocycle. A divergence point in the synthetic scheme also enabled access to a highly functionalized spiroaminal model system through an acid-mediated hydroxy oxo amide cyclization strategy. Copyright
- Aldrich, Leslie N.,Berry, Cynthia B.,Bates, Brittney S.,Konkol, Leah C.,So, Miranda,Lindsley, Craig W.
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supporting information
p. 4215 - 4218
(2013/07/26)
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- A very practical and selective method for PMB protection of alcohols
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A very simple, practical and efficient one-step heterogeneous protocol for the PMB protection of alcohols using Amberlyst-15 has been developed. The stability and hazard issues regarding PMBCl and PMBBr are totally avoided by directly using anisyl alcohol for the protection. Alcohols are protected in very good yields. The selective mono-PMB protection of diols as well as di-PMB protection of diols was achieved in good yields, along with the demonstration of recyclability of the catalyst.
- Chavan, Subhash P.,Harale, Kishor R.
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experimental part
p. 4683 - 4686
(2012/09/05)
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- The first total synthesis of Topsentolide B3
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The first total synthesis of the cytotoxic oxylipin Topsentolide B 3 has been accomplished in 15 steps with an overall yield of 24%. Starting with readily available cis-butene diol as a synthon, the synthesis involved Marouka allylation and Sha
- Sreedhar, Eppakayala,Venkanna, Arramshetti,Chandramouli, Nagula,Babu, K. Suresh,Rao, Janaswamy Madhusudana
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experimental part
p. 1078 - 1083
(2011/03/22)
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- Total synthesis of (+)-chloriolide
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The first total synthesis of (+)-chloriolide, a 12-membered macrolide from Chloridium virescens (var. chlamydosporum), was accomplished in a longest linear sequence of 20 steps from commercial materials in 7% overall yield. The Royal Society of Chemistry.
- Haug, Timm T.,Kirsch, Stefan F.
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supporting information; experimental part
p. 991 - 993
(2010/06/15)
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- In situ generation of novel acyclic diaminocarbene-copper complex
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A novel acyclic diaminocarbene-copper complex appears to be generated from a chloroamidinium salt and Cu(i)-thiophenecarboxylate in the presence of Grignard reagent based on 13C NMR studies and is a highly efficient catalyst for SN2′
- Hirsch-Weil, Dimitri,Snead, David R.,Inagaki, Sebastien,Seo, Hwimin,Abboud, Khalil A.,Hong, Sukwon
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supporting information; experimental part
p. 2475 - 2477
(2009/09/30)
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- Allylic fluorination via an unusual alkene Z/E isomerisation
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The isomerisation of readily available (Z)-4-(para-methoxybenzyloxy)-1-chloro-2-butene was achieved under mild conditions to afford the much less accessible E-diastereoisomer. This was an effective substrate in Sharpless asymmetric dihydroxylation (AD) re
- Laurenson, James A.B.,Meiries, Sebastien,Percy, Jonathan M.,Roig, Ricard
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scheme or table
p. 3571 - 3573
(2009/12/01)
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- Synthesis of the C19-C34 segment of amphidinolide C
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The synthesis of the C19-C34 segment of amphidinolide C is described. The key steps include the Mioskowski's Lewis acid catalyzed epoxide opening with the alcohol, ring-closing metathesis, Wittig reaction, and Nozaki-Hiyama-Kishi coupling reaction. Georg
- Mohapatra, Debendra K.,Rahaman, Hasibur,Chorghade, Mukund S.,Gurjar, Mukund K.
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p. 567 - 570
(2007/10/03)
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- Total synthesis of (+)-amphidinolide A. Assembly of the fragments
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The structure elucidation of (+)-amphidinolide A, a cytotoxic macrolide, has been accomplished by employing a combination of total synthesis and NMR spectroscopic analysis. Amphidinolide A possesses two skipped 1,4-diene subunits which are accessible by ruthenium-catalyzed alkene-alkyne couplings. Previous total syntheses had revealed that the reported structure was incorrect; therefore, to incorporate maximum flexibility into the synthesis, with the ultimate goal of determining the correct structure, a highly convergent approach was chosen. Furthermore, liberal use was made of catalytic asymmetric transformations to set individual stereocenters. Three different strategies were envisioned for the end game, and due to the highly convergent nature of the synthesis, all three routes disconnect to the same three key intermediates, 5, 6, and 7. Diastereomers of 6 and 7 were easily prepared by modification of the synthetic routes to allow access to multiple diastereomers of 1 for structural determination.
- Trost, Barry M.,Wrobleski, Stephen T.,Chisholm, John D.,Harrington, Paul E.,Jung, Michael
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p. 13589 - 13597
(2007/10/03)
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- Synthesis of the C6-C21 segment of amphidinolide E
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(Chemical Equation Presented) A convergent approach to a C6-C21 segment of the polyketide amphidinolide E has been developed through combination of three subunits by allenylindium bromide-aldehyde addition and Suzuki sp 2-sp3 couplin
- Marshall, James A.,Schaaf, Gregory,Nolting, Andrew
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p. 5331 - 5333
(2007/10/03)
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- Bismuth(III) chloride catalyzed efficient and selective cleavage of trityl ethers
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A highly selective and efficient protocol has been developed for detritylation using 5 mol% BiCl3 in acetonitrile. The cleavage proceeds at room temperature in high yields and the conditions are mild enough to tolerate a variety of acid-base sensitive functional groups.
- Sabitha, Gowravaram,Reddy, E. Venkata,Swapna,Reddy, N. Mallikarjun,Yadav
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p. 1276 - 1278
(2007/10/03)
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- Synthesis of diastereomerically and enantiomerically pure 2,3-disubstituted tetrahydrofurans using a sulfoxonium ylide
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Nucleophilic substitution reactions of 2,3-epoxy alcohols, easily prepared via Sharpless asymmetric epoxidation chemistry, offer access to a wide variety of enantiomerically pure compounds. In this communication, we describe the use of a Payne rearrangement to control regioselectivity in the ring-opening of a series of 2,3-epoxy alcohols with dimethylsulfoxonium methylide to yield diastereomerically and/or enantiomerically pure disubstituted tetrahydrofuran rings. The factors influencing the success and substitution pattern of the THF ring products are discussed, including steric, electronic, and solvent effects. Copyright
- Schomaker, Jennifer M.,Pulgam, Veera Reddy,Borhan, Babak
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p. 13600 - 13601
(2007/10/03)
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- Solid-phase access to polyhydroxypyrrolizidines by 1,3-dipolar cycloaddition of (S)-3-alkoxypyrroline N-oxide to maleate and crotonate derivatives
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2,7-Dihydroxyhexahydropyrrolizine-1-carboxylic acid derivatives have been prepared in solid-phase by intermolecular 1,3-dipolar cycloaddition between an immobilised maleate or 4-hydroxycrotonate and an enantiopure 3-alkoxypyrroline N-oxide.
- Pisaneschi, Federica,Della Monica, Carmela,Cordero, Franca M,Brandi, Alberto
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p. 5711 - 5714
(2007/10/03)
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- Ruthenium-catalyzed alkene-alkyne coupling: Synthesis of the proposed structure of amphidinolide A
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The ruthenium-catalyzed alkene-alkyne coupling provides a powerful method for the synthesis of 1,4 dienes and a way to simplify synthetic strategy. The latter potential is explored in the context of a synthesis of the assigned structure of amphidinolide A
- Trost, Barry M.,Chisholm, John D.,Wrobleski, Stephen T.,Jung, Michael
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p. 12420 - 12421
(2007/10/03)
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- Synthesis of the first photo-triggered pro-mitosene based on FR-900482
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A stereocontrolled synthesis of an eight-membered ring precursor to a photo-triggered mitosene is described. (C) 2000 Elsevier Science Ltd.
- Williams, Robert M.,Rollins, Samuel B.,Judd, Ted C.
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p. 521 - 532
(2007/10/03)
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- Synthetic studies on FR 900482. Synthesis of a photo-triggered pro-mitosene
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A stereocontrolled synthesis of an eight-membered ring precursor to a photo-triggered mitosene is described.
- Rollins, Samuel B.,Williams, Robert M.
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p. 4033 - 4036
(2007/10/03)
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- Total synthesis of an enantiomeric pair of FR980482. 2. Syntheses of the aromatic and the optically active aliphatic segments
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The synthesis of the aromatic segment 4 was achieved starting from commercially available 5-hydroxyisophthalic acid (6) by utilizing Claisen rearrangement of 9, bromolactonization of 12, and modified Curtius rearrangement of 16 as the key steps. Furthermore, the optically active aliphatic segments 5 and ent-5 were synthesized in enantiomerically pure forms starting with natural (2R, 3R)- and unnatural (2S, 3S)-diethyl tartrate (7 and ent-7), respectively: The synthetic scheme features epoxide formation of 26, nucleophilic epoxide opening of 27 with an azide anion, reduction of the azide function in 33 to an amine, and formation of the N-protected 1,3-oxazolidine 35.
- Yoshino, Toshiharu,Nagata, Yuriko,Itoh, Etsuko,Hashimoto, Masaru,Katoh, Tadashi,Terashima, Shiro
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p. 10239 - 10252
(2007/10/03)
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- Total synthesis of natural (+)-FR900482. 2. Efficient syntheses of the aromatic and the optically active aliphatic fragments
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The synthesis of the aromatic fragment 4 was achieved starting from commercially available 5-hydroxy-isophthalic acid (6) by utilizing Claisen rearrangement of 9, bromolactonization of 12, and modified Curtius rearrangement of 16 as key steps. Furthermore, the optically active aliphatic fragment 5 was synthesized in an optically pure form starting with L-diethyl tartrate (7) by featuring epoxide formation of 26, nucleophilic epoxide opening of 27 with an azide anion, reduction of the azide function in 33 to an amine, and formation of the N-protected 1,3-oxazolidine 35.
- Yoshino, Toshiharu,Nagata, Yuriko,Itoh, Etsuko,Hashimoto, Masaru,Katoh, Tadashi,Terashima, Shiro
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p. 3475 - 3478
(2007/10/03)
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- STEREOSPECIFIC SYNTHESIS OF A RIBOSYL-DIAZEPANONE DERIVATIVE; A SYNTHETIC APPROACH FOR ELUCIDATION OF THE STEREOCHEMISTRY OF A LIPID NUCLEOSIDE ANTIBIOTIC LIPOSIDOMYCIN B
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A new type of ribosyl-diazepanone derivative (23), the core ribosyl 7-membered heterocycle of the nucleoside antibiotic liposidomycin B has been synthesized using a chiral synthetic route that could offer accessibility to any of possible stereoisomers of
- Spada, Marianne R.,Ubukata, Makoto,Isono, Kiyoshi
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p. 1147 - 1167
(2007/10/02)
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