501072-27-1Relevant academic research and scientific papers
Metal-free synthesis of activated ynesulfonamides and tertiary enesulfonamides
Andna, Lucile,Miesch, Laurence
, p. 5688 - 5692 (2019)
An operationally simple synthesis of activated ynesulfonamides and enesulfonamides is described. Ynesulfonamides can be obtained through reaction of sulfonylamides with activated bromoalkynes and Triton B in a short time at room temperature. Likewise, terminal alkynes react with sulfonylamides to provide enesulfonamides. Z/E enesulfonamides can be transformed exclusively into E enesulfonamides.
Asymmetric transfer hydrogenation of unsaturated ketones; factors influencing 1,4- vs 1,2- regio- and enantioselectivity, and alkene vs alkyne directing effects
Hall, Thomas H.,Adams, Hannah,Vyas, Vijyesh K.,Michael Chu,Wills, Martin
supporting information, (2020/12/07)
A detailed study has been completed on the asymmetric transfer hydrogenation (ATH) of a series of enones using Ru(II) catalysts. Electron-rich rings adjacent to the C[dbnd]O group reduce the level of C[dbnd]O reduction compared to C[dbnd]C. The ATH reaction can readily discriminate between double and triple bonds adjacent to ketones, reducing the double bond but leaving a triple bond intact in the major product.
Catalytic asymmetric enyne addition to aldehdyes and Rh(I)-catalyzed stereoselective domino Pauson-Khand/[4 + 2] cycloaddition
Chen, Wei,Tay, Jia-Hui,Ying, Jun,Yu, Xiao-Qi,Pu, Lin
, p. 2256 - 2265 (2013/04/24)
The 1,1′-bi-2-naphthol-ZnEt2-Ti(OiPr) 4-Cy2NH system is found to catalyze the 1,3-enyne addition to aliphatic aldehydes as well as other aldehydes at room temperature with 75-96% yield and 82-97% ee. This system is also broadly applicable for the highly enantioselective reaction of other alkyl-, aryl-, and silylalkynes with structurally diverse aldehydes. The propargylic alcohols prepared from the catalytic asymmetric enyne addition to aliphatic aldehydes are used to prepare a series of optically active trienynes. In the presence of a catalytic amount of [RhCl(CO)2]2 and 1 atm of CO, the optically active trienynes undergo highly stereoselective domino Pauson-Khand/[4 + 2] cycloaddition to generate optically active multicyclic products. The Rh(I) catalyst is also found to catalyze the coupling of a diyne with CO followed by [4 + 2] cycloaddition to generate an optically active multicyclic product. These transformations are potentially useful for the asymmetric synthesis of polyquinanes containing a quaternary chiral carbon center.
Rhodium-catalyzed intra- and intermolecular [5 + 2] cycloaddition of 3-acyloxy-1,4-enyne and alkyne with concomitant 1,2-acyloxy migration
Shu, Xing-Zhong,Li, Xiaoxun,Shu, Dongxu,Huang, Suyu,Schienebeck, Casi M.,Zhou, Xin,Robichaux, Patrick J.,Tang, Weiping
supporting information; experimental part, p. 5211 - 5221 (2012/05/05)
A new type of rhodium-catalyzed [5 + 2] cycloaddition was developed for the synthesis of seven-membered rings with diverse functionalities. The ring formation was accompanied by a 1,2-acyloxy migration event. The five- and two-carbon components of the cycloaddition are 3-acyloxy-1,4-enynes (ACEs) and alkynes, respectively. Cationic rhodium(I) catalysts worked most efficiently for the intramolecular cycloaddition, while only neutral rhodium(I) complexes could facilitate the intermolecular reaction. In both cases, electron-poor phosphite or phosphine ligands often improved the efficiency of the cycloadditions. The scope of ACEs and alkynes was investigated in both the intra- and intermolecular reactions. The resulting seven-membered-ring products have three double bonds that could be selectively functionalized.
Iron-catalyzed C-O bond activation for the synthesis of propargyl-1,2,3-triazoles and 1,1-bis-triazoles
Yan, Wuming,Wang, Qiaoyi,Chen, Yunfeng,Petersen, Jeffrey L.,Shi, Xiaodong
supporting information; experimental part, p. 3308 - 3311 (2010/10/19)
(Equation Presented). The FeCl3-catalyzed triazole propargylation was developed. This transformation was suitable for a large scope of substituted propargyl alcohols, giving the corresponding propargyl triazoles in excellent yields (up to 96%). Further derivatization produced the 1,1-bis-triazoles in excellent yields and regioselectivity, which could be applied as potential transition metal ligands or new reagents.
Synthesis of 2,3-dihydrothiopyran-4-ones from 3-oxo-1-pentene-4-ynes
Rosiak, Anna,Mueller, Ralf M.,Christoffers, Jens
, p. 13 - 26 (2007/10/03)
3-Oxo-1-pentene-4-ynes were converted with sodium sulfide or hydrogensulfide to give 2,6-disubstituted 2,3-dihydrothiopyran-4-one derivatives. The starting materials were prepared in two steps from terminal alkynes and α,β-unsaturated aldehydes.
Synthesis of unsymmetrically 2,6-disubstituted 2,3-dihydrothiopyran-4-ones
Rosiak, Anna,Christoffers, Jens
, p. 5095 - 5097 (2007/10/03)
A series of 2,3-dihydrothiopyran-4-one derivatives with unequal substituents in the 2- and 6-position have been prepared by double conjugate addition of sulfide to enynones. These starting materials were accessed in two steps from terminal alkynes and α,β
Synthesis of unsymmetrically substituted 1,3-butadiynes and 1,3,5-hexatriynes via alkylidene carbenoid rearrangements
Shi Shun, Annabelle L. K.,Chernick, Erin T.,Eisler, Sara,Tykwinski, Rik R.
, p. 1339 - 1347 (2007/10/03)
Unsymmetrically substituted 1,3-butadiynes and 1,3,5-hexatriynes are synthesized in four steps from commercially available aldehydes or carboxylic acids. The key step in this process involves a Fritsch-Buttenberg-Wiechell rearrangement, in which an alkylidene carbenoid intermediate subsequently rearranges to the desired polyyne. This rearrangement proceeds under mild conditions, and it is tolerant of a range of functionalities. In general, the procedurally facile formation of the dibromoolefinic precursors, in combination with the effectiveness of the rearrangement step, makes this procedure an attractive alternative to traditional methods for di- and triyne synthesis that utilize palladium or copper catalysis.
