共查询到20条相似文献,搜索用时 609 毫秒
1.
Cong H Ledbetter D Rowe GT Caradonna JP Porco JA 《Journal of the American Chemical Society》2008,130(29):9214-9215
An efficient approach to cyclohexenyl chalcones employing highly electron rich 2'-hydroxychalcone dienophiles via electron transfer-initiated Diels-Alder cycloaddition is described. Using the methodology, the total synthesis of nicolaiodesin C has been accomplished. 相似文献
2.
[reaction: see text] Regioselective and stereoselective inverse-electron-demand Diels-Alder reaction of N-sulfonyl-1-aza-1,3-butadiene with fulvenes are described. The methodology provides an efficient and novel route to tetrahydro-[1]pyrindine systems. 相似文献
3.
Fen TanFang Li Xiao-Xiao ZhangXu-Fan Wang Hong-Gang ChengJia-Rong Chen Wen-Jing Xiao 《Tetrahedron》2011,67(2):446-451
A Brønsted acid catalyzed Diels-Alder reaction of 2-vinylindoles and 3-nitrocoumarins has been described. The methodology allows a rapid and expedient synthesis of a variety of coumarin-fused polycyclic indoles in good yields (up to 82%) with high diastereoselectivities (up to >19:1). 相似文献
4.
Adeva M Sahagún H Caballero E Peláez-Lamamié De Clairac R Medarde M Tomé F 《The Journal of organic chemistry》2000,65(11):3387-3394
The preparation of a range of open analogues of arcyriaflavin A is described. The synthetic approach is based on the use of perhydroisoindole-1,3,5-triones as key intermediates, which were obtained via Diels-Alder methodology using 1-aryl-3-siloxy-1, 3-butadienes as starting materials. Fischer indolization and aromatization processes afforded different methoxy-substituted arylpyrrolocarbazoles. The stereochemistry and conformation of the Diels-Alder products and the regiochemistry of the indolization reactions are supported by NMR and molecular modeling studies. 相似文献
5.
Dr. Pascal Vermeeren Dr. Trevor A. Hamlin Prof. Dr. F. Matthias Bickelhaupt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(40):e202200987
The catalytic effect of ionization on the Diels-Alder reaction between 1,3-butadiene and acrylaldehyde has been studied using relativistic density functional theory (DFT). Removal of an electron from the dienophile, acrylaldehyde, significantly accelerates the Diels-Alder reaction and shifts the reaction mechanism from concerted asynchronous for the neutral Diels-Alder reaction to stepwise for the radical-cation Diels-Alder reaction. Our detailed activation strain and Kohn-Sham molecular orbital analyses reveal how ionization of the dienophile enhances the Diels-Alder reactivity via two mechanisms: (i) by amplifying the asymmetry in the dienophile's occupied π-orbitals to such an extent that the reaction goes from concerted asynchronous to stepwise and thus with substantially less steric (Pauli) repulsion per reaction step; (ii) by enhancing the stabilizing orbital interactions that result from the ability of the singly occupied molecular orbital of the radical-cation dienophile to engage in an additional three-electron bonding interaction with the highest occupied molecular orbital of the diene. 相似文献
6.
The first examples of using aryl allenes as dienophiles in the electron transfer induced Diels-Alder reaction are described. According to mechanistic tests the reaction proceeds via a cycloaddition of the diene+· to the allene. 相似文献
7.
Singh RS Adachi S Tanaka F Yamauchi T Inui C Harada T 《The Journal of organic chemistry》2008,73(1):212-218
allo-Threonine-derived O-acyl-B-phenyl-oxazaborolidinones are demonstrated to be powerful and highly enantioselective Lewis acid catalysts for the Diels-Alder reaction of simple acyclic enone dienophiles, expanding the scope of ketone dienophiles and dienes. With 10 to 20 mol % of catalyst, the Diels-Alder adducts are obtained in 76-98% ee with high endo-selectivity. The catalyst exhibits high activity for the reaction with the less reactive beta-substituted dienophiles and the less reactive 1,3-cycohexadiene and 1,3-butadiene derivatives. The application of the catalysts to the Diels-Alder reaction of furan is also described. 相似文献
8.
Silyl-substituted 1,3-butadienes are useful building blocks and are readily applied in several types of reactions such as Diels-Alder reaction, ene reaction and allylation. They can also participate in different tandem reactions such as Diels-Alder/allylation, ene/allylation, ene/allylation/Diels-Alder reaction, ene/allylation/ene reaction and ene/allylation/Diels-Alder/allylation reaction. This feature article reviews the synthesis of silyl-substituted 1,3-butadienes, and their applications in the reaction types mentioned above, involving a tandem Diels-Alder/ene/allylation process. This article also introduces some reactions of alkenylsilanes and allylsilanes for comparison and discussion about the tandem reaction. The tandem reactions described in this article are a powerful tool to construct complicated multicyclic compounds with high selectivity and high efficiency. 相似文献
9.
The thermal and catalyzed Diels-Alder reactions of (+)-apoverbenone (1) with isoprene, 2, 3-dimethyl-1,3-butadiene, (E)-piperylene, (E)-1-methoxy-1,3-butadiene and cyclopentadiene are described; structural analysis by 1H and 13C-NMR spectroscopy is reported, and the syn-anti and endo-exo diastereoselectivity of the reactions is discussed. 相似文献
10.
由于Diels-Alder反应具有一系列重要特点(原子经济性、热可逆性、立体选择性、立体专一性和区域选择性等),自从1928年被发现以来,该反应就一直是人们研究的热点。将其应用于聚合物的合成中,可制备一些具有特殊性能的Diels-Alder聚合物,人们在这方面作了大量的研究工作,取得了许多研究成果。本文首先根据不同的分类标准,对应用Diels-Alder反应制备聚合物的研究进行了分类,然后结合本课题组的相关研究工作,综述了近年来人们在该领域的研究进展,最后展望了其研究前景。 相似文献
11.
The successful stereocontrol of the Diels-Alder reaction of semicyclic dienes possessing a secondary and tertiary allylic magnesium alkoxide alcohol functionality and activated dienophiles such as methyl acrylate, methacrolein, acrolein, and N-phenylmaleimide is described. 相似文献
12.
《Tetrahedron letters》1986,27(40):4895-4898
The asymmetric Diels-Alder reaction of naphthoquinone derivative and diene in the presence of chiral boron reagent derived from B(OMe)3 and ( R, R)(+)-tartaric acid diamide has been described as a model for the enantioselective preparation of important tetracycline natural products. 相似文献
13.
Santhosh Kumar ChittimallaChun-Chen Liao 《Tetrahedron》2003,59(23):4039-4046
Regioselective Diels-Alder reactions of masked o-benzoquinones (MOBs) 2a-i derived from the corresponding 2-methoxyphenols 1a-i with acrylonitrile leading to highly functionalized bicyclo[2.2.2]octenone derivatives in high yields are described. 相似文献
14.
Seshi Reddy SurasaniRama Krishna Peddinti 《Tetrahedron letters》2011,52(36):4615-4618
Inverse-electron-demand Diels-Alder reaction of masked o-benzoquinones (MOBs) ensuing from the corresponding 4-halo-2-methoxyphenols with styrene, dihydrofuran and ethyl vinyl ether, butyl vinyl ether, phenyl vinyl sulfide and vinyl acetate to afford the highly functionalized halogen substituted bicylclo[2.2.2]octenones are described. 相似文献
15.
The Diels-Alder reaction of maldoxin with an isopropenylallene at 60-75 °C afforded an adduct closely related to chloropestolide A (24%) and a second adduct (0-11%) that underwent an ene reaction to generate the chloropupukeanolide D (11-22%) skeleton. The Diels-Alder reaction occurred with good selectively (>5:1) from a single face of maldoxin under much milder conditions than previously reported for the analogous dimethoxycyclohexadienone. Furthermore, the ene reaction took place under mild conditions, whereas the analogous Diels-Alder adduct from the dimethoxycyclohexadienone did not undergo an ene reaction. 相似文献
16.
Miguel Ángel AlonsoPilar López-Alvarado Carmen AvendañoJ.Carlos Menéndez 《Tetrahedron》2003,59(16):2821-2830
6-(3-Indolyl)quinolinequinone derivatives gave regioselective Diels-Alder reactions with a variety of dienophiles, yielding polycyclic carbazole derivatives. One-pot reactions, proceeding through a cascade of reactions including regioselective Michael and Diels-Alder steps, gave heptacyclic derivatives starting from indoles and 2,5,8(1H)-quinolinetriones. Double Diels-Alder reactions of 6-(3-indolyl)quinolinequinones and dihalobenzoquinones gave eleven-cycle products in one step. 相似文献
17.
[structure in text] The synthesis of several 4-vinylimidazoles via Stille cross-coupling reactions of the corresponding protected 4-iodoimidazoles with tributylvinylstannane is described. These heterocyclic dienes are shown to be effective partners in the Diels-Alder reaction, providing adducts in good yield and exhibiting useful levels of isomer selectivity and stereoselectivity (endo/exo). 相似文献
18.
Jeremy P. Scott Deborah C. Hammond Elizabeth M. Beck Karel M.J. Brands Antony J. Davies Ulf-H. Dolling Derek J. Kennedy 《Tetrahedron letters》2004,45(17):3345-3348
The efficient preparation of 4-aryl-4-phenylsulfonyl cyclohexanones, containing a quaternary sulfone-bearing carbon centre, is described. Their synthesis proceeds in 38-78% overall yield by way of three steps: (i) sulfinate alkylation; (ii) methylenation; and (iii) regioselective Diels-Alder condensation with 2-trimethylsiloxybutadiene. The scope and limitations of the one-pot Mannich-type methylenation described were examined. 相似文献
19.
Michael B. Wallace Nicholas Scorah Phong H. Vu Jason W. Brown Jeffrey A. Stafford Qing Dong 《Tetrahedron letters》2010,51(13):1739-1741
An efficient, versatile, and scalable route for the synthesis of 7-aza-α-carboline compounds is described. The tricyclic system has been prepared from modified pyrazinones using a key intramolecular [4+2] Diels-Alder transformation. 相似文献
20.
A study toward the unusual spirotetramate core of the pyrroindomycin antibiotics employing an intermolecular Diels-Alder reaction of an exo-methylene tetramic acid dienophile is described. The exo-methylene tetramate is readily synthesized from S-methylcysteine, and its reactivity as a dienophile is compared with that of related dehydroalanine derivatives. An alternative approach to spirotetramates using a nitroalkene dienophile is also reported. 相似文献