29021-82-7Relevant academic research and scientific papers
Synthesis and in vitro evaluation of (R), (S) and (R/S)-2-hexyne-1,4-diol, a natural product produced by fungus Clitocybe catinus, and related analogs as potential anticancer agents
Princival, Iza Mirela R.G.,Ferreira, Jeiely G.,Silva, Teresinha G.,Aguiar, Jaciana S.,Princival, Jefferson L.
, p. 2839 - 2842 (2016)
The search for natural products and related analogs as potential anticancer agents has seen a significant growth worldwide. Since small sized propargylic diols can be found in nature and chemically synthesized, their evaluation against cancer cells has been of great interest, being a topic of relevance to be investigated. For this purpose, a scalable approach aiming at the synthesis of several propargylic diols and their bioactivity against seven tumor cell lines were evaluated. Interestingly, when the compound 1a, a natural product produced by fungus Clitocybe catinus, was tested in its racemic mixture a more effective activity was observed if compared when enantiopure R-1a or S-1a were tested separately.
CeCl3-mediated addition of acetylenic bis-lithium salts to aldehydes and ketones: An efficient route to bis-substituted alkyne diols
Princival, Jefferson Luiz,Ferreira, Jeiely Gomes
, p. 3525 - 3528 (2017)
An efficient, chemoselective protocol to access propargylic diols via a CeCl3-mediated addition reaction is reported. Propargylic alcohols were transformed into the corresponding acetylenic bis-lithium salt intermediates, which react with aldehydes and ketones in the presence of dry CeCl3 to furnish the corresponding bis-substituted alkyne diols. This protocol does not involve protection-deprotection or transmetallation steps, and allows the use of poorly reactive or highly enolizable substrates.
Iron-catalyzed sustainable synthesis of pyrrole
Emayavaramban, Balakumar,Sen, Malay,Sundararaju, Basker
supporting information, p. 6 - 9 (2017/11/28)
Efficient, sustainable, highly regiospecific substituted pyrroles were synthesized using a well-defined, air stable, molecular iron(0) complex. The developed methodology is broadly applicable and tolerates a variety of functional groups. C-2, C-3, and C-2 & C-4 substituted pyrroles were synthesized in good yield. Symmetrical bis-pyrroles were accessible for the first time using an iron catalyst. On the basis of the experimental observation, we propose that the reaction proceeds through a hydrogen autotransfer process followed by second oxidation/ intramolecular dehydrative condensation to provide the pyrrole.
Enantioselective Isothiourea-Catalysed Michael-Michael-Lactonisation Cascade Reaction for the Synthesis of δ-Lactones and 1,2,3,4-Substituted Cyclopentanes
Robinson, Emily R. T.,Frost, Aileen B.,Elías-Rodríguez, Pilar,Smith, Andrew D.
supporting information, p. 409 - 423 (2016/12/24)
This manuscript describes the application of α,β-unsaturated acyl ammonium intermediates in a Michael-Michael-lactonisation cascade process to furnish δ-lactones. Generation of α,β-unsaturated acyl ammonium intermediates was achieved upon addition of isothiourea catalyst HyperBTM into α,β-unsaturated acid chlorides. Subsequent reaction with enone-malonates gave access to δ-lactones in 20-64% yield, 72.5:27.5 to 95:5 er and 81:19 to >95:5 dr. Additionally, application of a ring-opening protocol yielded 1,2,3,4-substituted cyclopentanes in 28-77% yield, 76:24 to 98:2 er and 86:14 to >95:5 dr. Interestingly, the highest er was observed at high reaction temperatures, with 70°C proving optimal. This effect was investigated by conducting an Eyring analysis, which indicated that differential activation entropy rather than differential activation enthalpy is responsible for enantiodiscrimination in this process.
Palladium-catalyzed [4 + 2] cycloaddition of aldimines and 1,4-dipolar equivalents via amphiphilic allylation
Hirata, Goki,Yamada, Naoshi,Sanada, Shohei,Onodera, Gen,Kimura, Masanari
supporting information, p. 600 - 603 (2015/03/04)
The combination of Pd catalyst and diethylzinc with triethylborane promotes the amphiphilic allylation of aldimines with 2,3-bismethylenebutane-1,4-diol derivatives to serve as bis-allylic zwitterion species to form 3,4-bismethylenepiperidines via a formal [4 + 2] cycloaddition reaction. 3,4-Bismethylenepiperidine rings are applicable for the synthesis of isoquinoline derivatives via the Diels-Alder reaction followed by an oxidation reaction with DDQ.
Some special features of hydroalumination-iodination of alkyne-1,4-diols
Gharibyan,Makaryan,Hovhannisyan,Kinoyan,Chobanyan
, p. 457 - 464 (2014/05/20)
Hydroalumination-iodination of alkyne-1,4-diols of different structure showed that with increasing number of substituents at the C-OH group the amount of β-iodo-substituted products with respect to this group increased. In the case of symmetric secondary 1,4-diols the reaction results in a 1: 1 mixture of stereoisomeric iodoalkenediols, and in the case of phenyl substituents the reaction proceeds regio- and stereoselectively to give an alkenediol iodine atom in the β-position to phenyl group.
Regio- and diastereoselective copper(I)-catalyzed allylic substitution of δ-hydroxy allylic chlorides by a silicon nucleophile
Hazra, Chinmoy K.,Irran, Elisabeth,Oestreich, Martin
supporting information, p. 4903 - 4908 (2013/08/23)
A perfectly γ-selective copper(I)-catalyzed allylic substitution of protected δ-hydroxy allylic chlorides with a silicon nucleophile generated by Si-B bond activation provides diastereoselective access to β-hydroxy α-chiral allylic silanes with an anti re
Synthesis of cyclic N-tosyliminocarbonates by Lewis acid catalyzed allylic substitution of trichloroacetimidates
Grigorjeva, Liene,Jirgensons, Aigars
supporting information, p. 5307 - 5316 (2012/10/30)
Allylic trichloroacetimidates bearing a δ-N-tosylcarbamoyloxy group were prepared in two steps from the corresponding diols, and their Bronsted and Lewis acid catalyzed cyclization reactions were investigated. It was found that N-tosylcarbamates derived from secondary and tertiary alcohols bearing alkyl substituents undergo a chemoselective allylic alkylation to give N-tosyliminocarbonates in good isolated yields. In turn, aryl-substituted substrates tend to give oxazolines by abstraction of the carbamate functionality. The cyclization of N-tosylcarbamates derived from secondary alcohols preferentially give trans-iminocarbonates. However, the trans selectivity varied and depended on the substitution pattern, configuration of the substrate, and the catalyst. A high trans selectivity could be achieved from (E) substrates by using TMSOTf as the catalyst. The synthetic utility of iminocarbonates was demonstrated by transforming them into 1,2-diols and cyclic carbonates as well as into N-tosyloxazolidinones by a halide ion-induced rearrangement. Copyright
Lewis acid catalyzed intramolecular allylic substitution of bis(trichloroacetimidates): A versatile approach to racemic unsaturated amino acids
Grigorjeva, Liene,Jirgensons, Aigars
supporting information; experimental part, p. 2421 - 2425 (2011/06/10)
Lewis acid catalyzed cyclization of trichloroacetimidates derived from 1,4-butenediols and 1,5-butenediols was achieved to give 4-vinyl oxazolines and 4-vinyloxazines in good to excellent yields. The cyclization products were transformed to protected unsaturated α- and β-amino acids, thus demonstrating the novel approach to access these important classes of compounds. Lewis acid catalyzed cyclization of allylic bis(trichloroacetimidates) (n = 1, 2) provides 4-vinyloxazolines and 4-vinyloxazines. The products of cyclization weredemonstrated to be versatile intermediates for the synthesis of unsaturated α- and β-amino acids. Copyright
Facile synthesis of dihaloheterocycles via electrophilic iodocyclization
Yang, Fan,Jin, Tienan,Bao, Ming,Yamamoto, Yoshinori
supporting information; scheme or table, p. 10147 - 10155 (2012/01/03)
An efficient and facile electrophilic iodocyclization for the synthesis of various O-, N-, and S-containing dihaloheterocycles has been developed. A wide range of the substituted propargyl alcohols having -OH, -NTs, and -SAc functional groups reacted with molecular iodine or bromoiodine at ambient temperature to produce the corresponding dihalogenated O-, N-, and S-containing five- and six-membered heterocycles in good to high yields; Under optimized solvent conditions, the reactions of various substituted but-2-yn-1-ones bearing -OH, -NTs, and -SAc functional groups at C4-position, with iodine or bromoiodine at ambient temperature afforded the corresponding 3,4-diiodo- and 3-bromo-4-iodo-substituted furans, pyrroles, and thiophenes in good to high yields. Further transformation of the resulting iodine- or bromine-containing products to polyaromatics potentially of useful as organo-material intermediates has been investigated.
