共查询到20条相似文献,搜索用时 31 毫秒
1.
Qin Yin Shou-Guo Wang Xiao-Wei Liang De-Wei Gao Jun Zheng Shu-Li You 《Chemical science》2015,6(7):4179-4183
An organocatalytic asymmetric chlorinative dearomatization of naphthols was realized for the first time, providing chiral naphthalenones with a Cl-containing all-substituted stereocenter in excellent yields and enantioselectivity (up to 97% yield and 96% ee). The reaction features mild reaction conditions, good tolerance of diverse functional groups and simple reaction operation. 相似文献
2.
Chiral BINOL-derived Br?nsted acids catalyze the enantioselective asymmetric Morita-Baylis-Hillman (MBH) reaction of cyclohexenone with aldehydes. The asymmetric MBH reaction requires 2-20 mol % of the chiral Br?nsted acid 2e or 2f and triethylphosphine as the nucleophilic promoter. The reaction products are obtained in good yields (39-88%) and high enantioselectivities (67-96% ee). The Br?nsted-acid-catalyzed reaction is the first example of a highly enantioselective asymmetric MBH reaction of cyclohexenone with aldehydes. 相似文献
3.
Cinchona alkaloids catalyze the enantioselective Mannich reaction of beta-keto esters with acyl aryl imines. The reaction requires 10 mol % of cinchonine or cinchonidine. The reaction products are obtained in good yields (81-99%), high enantioselectivities (80-96% ee), and in diastereoselectivities that range from 1:1 to >95:5. The cinchonine-catalyzed reaction provides access to highly functionalized building blocks used in the asymmetric synthesis of a dihydropyrimidone and beta-amino alcohol. 相似文献
4.
We report the first efficient enantioselective Friedel-Crafts hydroxyalkylation of pyrroles having one electron-withdrawing group at the α, β or N-positions with alkyl glyoxylates catalyzed by readily available chiral BINOL-Ti(IV) complexes (1-5 mol %). The reaction regioselectively led to the desired pyrrole-hydroxyacetic acid derivatives with good yields (70-96%) and enantiomeric excesses up to 96%, and is applicable in multigram scale with low loading of the catalyst (1 mol %). 相似文献
5.
The asymmetric arylation of N-tosylarylimines with arylboronic acids was realized by using rhodium/(S)-ShiP as catalyst. The reaction proceeded in aqueous toluene to give diarylmethylamines in good yields with up to 96% ee. [reaction: see text] 相似文献
6.
Isoquinoline reacts with diaroylacetylenes in the presence of 1,3-dicarbonyl compounds in a one-pot reaction to afford functionalized spiropyrroloisoquinolines in 90-96% yields. 相似文献
7.
Newly-developed bis(thiourea) 1d was found to be an efficient organocatalyst for the Morita-Baylis-Hillman reaction. High enantioselectivities were obtained in the reaction of 2-cyclohexen-1-one with both aromatic aldehydes (up to 84% ee) and aliphatic aldehydes (up to 96% ee). 相似文献
8.
Highly Enantioselective Intermolecular Cross Rauhut–Currier Reaction Catalyzed by a Multifunctional Lewis Base Catalyst 下载免费PDF全文
Xuelin Dong Ling Liang Erqing Li Prof. Dr. You Huang 《Angewandte Chemie (International ed. in English)》2015,54(5):1621-1624
The highly enantioselective intermolecular cross Rauhut–Currier reaction of different active olefins catalyzed by a multifunctional chiral Lewis base was reported. The RC products were obtained in excellent yields (up to 98 %), high chemo‐ and enantioselectivity (up to 96 % ee). The reaction could be performed on a gram scale using 1 mol % of the multifunctional phosphine catalyst. 相似文献
9.
Karine Tissot-Croset 《Tetrahedron letters》2004,45(39):7375-7378
Methyl Grignard undergoes highly regio (>90/10) and enantioselective (ee 91-96%) copper catalyzed allylic substitution on cinnamyl-type chlorides. CuBr (3%) and 3.3% of a chiral phosphoramidite ligand are sufficient for a complete reaction. The synthesis of a precursor of (+)-Naproxen is described. The reaction can be extended to alkyl substituted allylic chlorides (ee 72%). 相似文献
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Rosalinde Imbos Adriaan J Minnaard Ben L Feringa 《Journal of the American Chemical Society》2002,124(2):184-185
An efficient enantioselective intramolecular Heck reaction of cyclohexadienones, using readily available and modular TADDOL-based mono- and bidentate phosphoramidites as chiral ligands and not requiring any additives, has been developed. Excellent enantioselectivities up to 96% ee are reached for the first time in a Heck reaction with monodentate ligands. 相似文献
13.
[reaction: see text] Polymer-supported bisBINOL ligands were successfully utilized for the immobilization of multicomponent asymmetric catalysts. The polymer-supported Al-Li-bis(binaphthoxide) (ALB) catalyst was more effective than the dendrimer-supported ALB in the Michael reaction of 2-cyclohexen-1-one with dibenzyl malonate affording the adduct in 91% yield with 96% ee. The polymer was also effective for the immobilization of a mu-oxodititanium complex that promoted carbonyl-ene reaction of ethyl glyoxalate with alpha-methyl styrene to provide the adduct with up to 98% ee. 相似文献
14.
A new bifunctional titanium/Schiff base catalyst was developed for the enantioselective cyanoformylation of aldehydes with ethyl cyanoformate. The reaction proceeded smoothly with a mild reaction condition to afford the cyanohydrin ethyl carbonates in high yields (up to 96%) and good enantioselectivities (up to 85% enantiomeric excess). Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
15.
The α′-acetoxylation of enones and the α-acetoxylation of aromatic ketones were carried out with potassium permanganate and acetic acid, in which acetoxylation products were obtained in 74-96% yields. The same reaction was carried out with carboxylic acids other than acetic acid, which furnished corresponding acyloxy ketones with the same regioselectivity. For the first time, formyloxylation products were synthesized in a 61-85% yield by using formic acid. The potassium permanganate and acetic acid method was also used for aryl coupling reactions. The reaction of arylboronic acids and arylhydrazines in benzene with potassium permanganate and acetic acid in turn furnished biaryls in 85-96% yield. We have shown that potassium permanganate/carboxylic acid/organic solvent behaves as manganese(III) acetate. 相似文献
16.
We report the first catalytic Sakurai reaction of N-alkoxycarbonylamino sulfones with allylsilanes. The allylation reaction of N-alkoxycarbonylamino phenylsulfones with allyltrimethylsilane proceeded smoothly with low catalyst loading of bismuth triflate (2.0 mol%) to afford the corresponding protected homoallylic amines in moderate to very good yields (up to 96%). 相似文献
17.
Peng L Wang LL Bai JF Jia LN Guo YL Luo XY Wang FY Xu XY Wang LX 《Organic & biomolecular chemistry》2011,9(13):4774-4777
A series of primary-tertiary diamine catalysts were successfully applied to promote the enantioselective aldol reaction of acetone with β,γ-unsaturated α-keto esters in excellent yields (up to 99%) and enantioselectivities (up to 96% ee). 相似文献
18.
Gerard Jaouen Brian F.G. Johnson Jack Lewis 《Journal of organometallic chemistry》1982,231(2):c21-c24
2,4-Cyclohexadien-1-yldimethylphenylphosphonium tetrafluoroborate obtained from the reaction of 2,4-cyclohexadien-1-yltricarbonyliron with PMe2Ph in 96% yield, reacts readily with benzaldehyde in the presence of base to give 1-benzylidiene-2,4-cyclohexadienetricarbonyliron in 90% yield; this and other related reactions provide the first examples of the Wittig reaction adjacent to a tricarbonyl moiety. 相似文献
19.
[reaction: see text] A general, high yielding rapid iron-catalyzed cross-coupling reaction between Grignard reagents and imidoyl chlorides is described. These reactions are typically completed within 5 min, resulting in high yields of 71-96% using 5% iron catalyst in a THF-NMP solvent mixture. Functionalized imidoyl chlorides (e.g., R = CO(2)Me) gave excellent yields (89%). 相似文献
20.
A Michael-type reaction of β,γ-unsaturated α-keto ester and α-nitro ketone was established. With a thiourea catalyst derived from cinchona alkaloid, the reactions afford products in 47-94% yields with 68-96% ee. 相似文献