5272-36-6Relevant articles and documents
Synthesis of cyclic polyelectrolyte via direct copper(I)-catalyzed click cyclization
Chen, Fenggui,Liu, Guangming,Zhang, Guangzhao
, p. 831 - 835 (2012)
Well-defined cyclic poly(acrylic acid) (PAA) has been successfully prepared based on the direct click cyclization. The linear poly(tert-butyl acrylate) (PtBA) with azide and TMS-protected alkyne group forms cyclic chain directly by the copper(I)-catalyzed click cyclization without any deprotection steps. Cyclic PAA is synthesized by the hydrolysis of cyclic PtBA. The present synthetic strategy provides a simple and efficient method to synthesize cyclic polyelectrolyte and can be applied to other polymer systems. Copyright
Silver-catalyzed heterocyclization: First total synthesis of the naturally occurring cis 2-hexadecyl-3-hydroxy-4-methylene butyrolactone
Dalla,Pale
, p. 3525 - 3528 (1994)
The title compound was obtained in 4 steps with an overall yield of 64% with the silver-catalyzed cyclization of the corresponding substituted β-hydroxy-γ-acetylenic acid as the key step.
Silicon-directed decarbonylation of trimethylsilyl β,γ-enals by photolysis
Hwu,Furth
, p. 8834 - 8841 (1989)
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Low-valent dialkoxytitanium(ii): a useful tool for the synthesis of functionalized seven-membered ring compounds
Bodinier, Florent,Sanogo, Youssouf,Ardisson, Janick,Lannou, Marie-Isabelle,Sorin, Geoffroy
supporting information, p. 3603 - 3606 (2021/04/14)
Herein, we describe unprecedented access to all-carbon or heterocyclic seven-membered ring frameworks from 1,8-ene-ynes promoted by inexpensive low-valent titanium(ii) species, readily available from Ti(OiPr)4and Grignard reagent. A broad range of cycloheptane, azepane or oxepane derivatives has been obtained (19 examples) with moderate to good yields and an excellent selectivity (up to 95/5 d.r.).
Development of a Radical Silylzincation of (Het)Aryl-Substituted Alkynes and Computational Insights into the Origin of the trans-Stereoselectivity
Romain, Elise,de la Vega-Hernández, Karen,Guégan, Frédéric,Sanz García, Juan,Fopp, Carolin,Chemla, Fabrice,Ferreira, Franck,Gerard, Hélène,Jackowski, Olivier,Halbert, Stéphanie,Oestreich, Martin,Perez-Luna, Alejandro
supporting information, p. 2634 - 2647 (2021/03/30)
Aryl- and hetaryl-substituted acetylenes undergo regio- and stereoselective silylzincation by reaction with [(Me3Si)3Si]2Zn in the presence of Et2Zn (10–110 mol%) as additive. The distinctive feature of this addition across the C?C triple bond is its trans stereoselectivity. The radical nature of the silylzincation process is supported by diagnostic experiments and DFT calculations, which also corroborate the role played by steric effects to obtain that stereoselectivity. The procedure can be combined in one-pot with the copper(I)-mediated electrophilic substitution of the C(sp2)?Zn bond, with retention of the double bond geometry. This makes it valuable for the synthesis of stereodefined di- and trisubstituted vinylsilanes. (Figure presented.).
Exploring the scope of tandem palladium and isothiourea relay catalysis for the synthesis of α-amino acid derivatives
Bitai, Jacqueline,Slawin, Alexandra M.Z.,Cordes, David B.,Smith, Andrew D.
supporting information, (2020/07/27)
The scope and limitations of a tandem N-allylation/[2,3]-rearrangement protocol are investigated through the incorporation of a variety of functional groups within an allylic phosphate precursor. This method uses readily accessible N,N-dimethylglycine aryl esters and functionalized allylic phosphates, forming quaternary ammonium salts in situ in the presence of a palladium catalyst. Subsequent enantioselective [2,3]-sigmatropic rearrangement, promoted by the chiral isothiourea tetramisole, generates α-amino acid derivatives with two contiguous stereocenters. The incorporation of electron-withdrawing ester and amide groups gave the best results, furnishing the desired products in moderate to good yields (29-70percent), with low diastereocontrol (typically 60:40 dr) but high enantioselectivity (up to 90:10 er). These results indicate that substrate-catalyst interactions in the proposed transition state are sensitive to the substitution pattern of the substrates.
