97943-16-3Relevant articles and documents
Morita–Baylis–Hillman-Type [3,3]-Rearrangement: Switching from Z- to E-Selective α-Arylation by New Rearrangement Partners
Zhang, Lei,Bao, Wangzhen,Liang, Yuchen,Pan, Wenjing,Li, Dongyang,Kong, Lichun,Wang, Zhi-Xiang,Peng, Bo
supporting information, p. 11414 - 11422 (2021/04/09)
α-aryl α,β-unsaturated carbonyls represent an important class of derivatizable synthetic intermediates, however, the synthesis of such compounds still remains a challenge. Recently, we showcased a novel Z-selective α-arylation of α,β-unsaturated nitriles with aryl sulfoxides via [3,3]-rearrangement involving an Morita–Baylis–Hillman (MBH) process. Herein, we demonstrate the feasibility of reversing the stereoselectivity of such MBH-type [3,3]-rearrangement by switching to a new pair of rearrangement partners consisting of aryl iodanes and α,β-unsaturated oxazolines. As a result, the two protocols complement each other in approaching E- or Z-α-aryl α,β-unsaturated carbonyl derivatives. Mechanistic studies reveal a possible reaction pathway and provide an explanation for the opposite stereoselectivities.
Modular Cyclopentenone Synthesis through the Catalytic Molecular Shuffling of Unsaturated Acid Chlorides and Alkynes
Lee, Yong Ho,Denton, Elliott H.,Morandi, Bill
supporting information, p. 20948 - 20955 (2020/12/21)
We describe a general strategy for the intermolecular synthesis of polysubstituted cyclopentenones using palladium catalysis. Overall, this reaction is achieved via a molecular shuffling process involving an alkyne, an α,β-unsaturated acid chloride, which serves as both the alkene and carbon monoxide source, and a hydrosilane to create three new C-C bonds. This new carbon monoxide-free pathway delivers the products with excellent yields. Furthermore, the regioselectivity is complementary to conventional methods for cyclopentenone synthesis. In addition, a set of regio- and chemodivergent reactions are presented to emphasize the synthetic potential of this novel strategy.
Design, synthesis, antiproliferative activity and docking studies of quinazoline derivatives bearing 2,3-dihydro-indole or 1,2,3,4-tetrahydroquinoline as potential EGFR inhibitors
OuYang, Yiqiang,Zou, Wensheng,Peng, Liang,Yang, Zunhua,Tang, Qidong,Chen, Mengzi,Jia, Shuang,Zhang, Hong,Lan, Zhou,Zheng, Pengwu,Zhu, Wufu
, p. 29 - 43 (2018/05/24)
Eight series of quinazoline derivatives bearing 2,3-dihydro-indole or 1,2,3,4-tetrahydroquinoline were designed, synthesized and evaluated for the IC50 values against three cancer cell lines (A549, MCF-7 and PC-3). Most of the forty nine target compounds showed excellent antiproliferative activity against one or several cancer cell lines. The compound 13a showed the best activity against A549, MCF-7 and PC-3 cancer cell lines, with the IC50 values of 1.09 ± 0.04 μM, 1.34 ± 0.13 μM and 1.23 ± 0.09 μM, respectively. Eight selected compounds were further selected to evaluated for the inhibitory activity against EGFR kinase. Three of them showed equal activity against EGFR kinase to positive control afatinib. AnnexinV-FITC, propidium iodide (PI) double staining and acridine orange single staining results indicated that the compound 13a could induce apoptosis of human lung cancer A549 cells.
Stereoselective Total Synthesis of Bisorbicillinoid Natural Products by Enzymatic Oxidative Dearomatization/Dimerization
Sib, Anna,Gulder, Tobias A. M.
supporting information, p. 12888 - 12891 (2017/09/14)
Natural products are a virtually inexhaustible source of small molecules with spectacular molecular architectures and biomedical potential. Their structural complexity generates formidable challenges to total synthesis but often also precludes time- and resource-efficient, stereoselective synthetic access. Biosynthetically, nature frequently uses dimerization and oligomerization reactions to produce highly challenging frameworks from simple starting materials. Impressive examples are the bisorbicillinoids, a family of fungal natural products thought to originate from the polyketide precursor sorbicillin. Utilizing the recombinant oxidoreductase SorbC from the sorbicillin biosynthetic gene cluster, a robust, fully stereoselective synthesis of bisorbicillinoid natural products and unnatural side-chain analogues was developed.
Intramolecular Nitrofuran Diels-Alder Reactions: Extremely Substituent-Tolerant Cycloadditions via Asynchronous Transition States
Cowie, Thomas Y.,Veguillas, Marcos,Rae, Robert L.,Rougé, Mathilde,Zurek, Justyna M.,Prentice, Andrew W.,Paterson, Martin J.,Bebbington, Magnus W. P.
, p. 6656 - 6670 (2017/07/15)
Nitrofurans undergo intramolecular Diels-Alder reactions with tethered electron-poor dienophiles more rapidly and in higher yield than non-nitrated furans. Computational studies indicate that increased stabilization of a partial positive charge on the nitro-substituted carbon in both transition state and product is the driving force for these reactions. Frontier molecular orbital energy differences indicate a switch from normal to inverse electron demand upon nitration. There does not appear to be a contribution from any differences in aromatic stabilization energy between furans and nitrofurans. Calculations show that the nitrofuran reactions proceed via a highly asynchronous transition state allowing easier bond formation between two sterically hindered carbons.
Lewis Acid Enabled Copper-Catalyzed Asymmetric Synthesis of Chiral β-Substituted Amides
Rodríguez-Fernández, Mamen,Yan, Xingchen,Collados, Juan F.,White, Paul B.,Harutyunyan, Syuzanna R.
supporting information, p. 14224 - 14231 (2017/10/17)
Here we report that readily available silyl- and boron-based Lewis acids in combination with chiral copper catalysts are able to overcome the reactivity issues of unactivated enamides, known as the least reactive carboxylic acid derivatives, toward alkyla
2H-pyran-2-ones from trichoderma viride and trichoderma asperellum
Wickel, Susanne M.,Citron, Christian A.,Dickschat, Jeroen S.
supporting information, p. 2906 - 2913 (2013/06/27)
Volatiles emitted by the soil fungi Trichoderma viride 272 and Trichoderma asperellum 328 were collected by using the closed loop stripping analysis (CLSA) headspace technique, and the obtained extracts were analysed by GC/MS. Several alkyl- and alkenyl-2H-pyran-2-ones, including known compounds 6-pentyl-2H-pyran-2-one and (E)-6-(pent-1-en-1-yl)-2H-pyran-2-one, and the new derivatives (E)-6-(pent-2-en-1-yl)-2H-pyran-2-one, 6-propyl-2H-pyran-2-one, and 6-heptyl-2H-pyran-2-one were found. The alkenyl derivative (E)-6-(hept-1-en-1- yl)-2H-pyran-2-one, previously tentatively identified from a marine Botrytis by MS analysis, was also detected. All alkenyl pyrones were synthesised by using a reported Stille coupling followed by lactonisation, whereas the alkylated pyrones were obtained through a reported synthetic approach by radical bromination of 5-alkylpent-2-en-5-olides and dehydrobromination. Because the yields in both cases were not satisfactory and fell a long way short of the yields reported for similar compounds, all compounds were synthesised again using a gold-catalysed coupling of terminal alkynes with propiolic acid recently developed by Schreiber and co-workers, giving high yields in all cases. A comparison of the synthetic methods is given. Copyright
Synthesis of β,γ-unsaturated primary amides from α,β-unsaturated acids and investigation of the mechanism
Theodorou, Vassiliki,Gogou, Marina,Philippidou, Maria,Ragoussis, Valentine,Paraskevopoulos, Georgios,Skobridis, Konstantinos
experimental part, p. 5630 - 5634 (2011/08/22)
α,β-Unsaturated acids, through their acid chlorides, react with tritylamine in the presence of triethylamine under mild conditions, to afford in high yield and high regioselectivity the corresponding β,γ- unsaturated tritylamides. Detritylation with TFA generates quantitatively β,γ-unsaturated primary amides. An investigation of this deconjugative isomerization was performed.
Use of the curtius rearrangement of acryloyl azides in the synthesis of 3,5-disubstituted pyridines: Mechanistic studies
Chuang, Ta-Hsien,Chen, Yu-Chi,Pola, Someshwar
supporting information; experimental part, p. 6625 - 6630 (2010/11/18)
A series of disubstituted pyridine derivatives was synthesized from the corresponding acryloyl azides by acetic acid-promoted cycloaddition. This represents a novel and convenient synthetic approach to the symmetric 3,5-disubstituted pyridines. The nature of the substituent on the double bond and the utilized solvent were found to be crucial to the yield of pyridines. The reactivity of the acid-promoted cycloaddition increases with the presence of aryl groups, such as phenyl and pyridinyl. We also explored the comprehensive mechanism by the acid-promoted cycloaddition of 13C-labeled cinnamoyl azide. The symmetric 3,5-disubstituted pyridines were synthesized from acryloyl azides by acetic acid-promoted trimolecular condensation.
Organocatalysis in conjugate amine additions. Synthesis of β-amino acid derivatives
Sibi, Mukund P.,Itoh, Kennosuke
, p. 8064 - 8065 (2008/02/09)
Conjugate addition of O-protected hydroxylamines to pyrazole-derived enoates proceeds with high efficiency and enantioselectivity when chiral thioureas are used as activators. A wide variety of substrates undergo conjugate amine addition providing access to enantioenriched β-amino acid derivatives. Structural requirements for the optimal thiourea catalyst have been established, and the results suggest that it operates as a bifunctional catalyst. Copyright
