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Simultaneous Induction of Axial and Planar Chirality in Arene–Chromium Complexes by Molybdenum‐Catalyzed Enantioselective Ring‐Closing Metathesis 下载免费PDF全文
Prof.Dr. Ken Kamikawa Dr. Sachie Arae Dr. Wei‐Yi Wu Chihiro Nakamura Prof.Dr. Tamotsu Takahashi Prof.Dr. Masamichi Ogasawara 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):4954-4957
The molybdenum‐catalyzed asymmetric ring‐closing metathesis of the various Cs‐symmetric (π‐arene)chromium substrates provides the corresponding bridged planar‐chiral (π‐arene)chromium complexes in excellent yields with up to >99 % ee. With a bulky and unsymmetrical substituent, such as N‐indolyl or 1‐naphthyl, at the 2‐positions of the η6‐1,3‐diisopropenylbenzene ligands, both biaryl‐based axial chirality and π‐arene‐based planar chirality are simultaneously induced in the products. The axial chirality is retained even after the removal of the dicarbonylchromium fragment, and the chiral biaryl/heterobiaryl compounds are obtained with complete retention of the enantiopurity. 相似文献
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Marvin Fresia Dr. Mario Kock Prof. Dr. Thomas Lindel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(56):12733-12737
The enantioselective synthesis of (−)-dihydroraputindole D is reported. The key step is the desymmetrizing benzoylation of a prochiral 1,3-diol employing Trost′s ProPhenol catalyst system, which has been applied for the first time to a cyclic molecule carrying geminal hydroxymethyl groups. The cyclopenta[f]indoline system was assembled by Au(I)-catalyzed cyclization of an alkynylated indoline precursor. (−)-Dihydroraputindole D was obtained in 17 steps and 8% overall yield starting from dihydroxyacetone. In combination with quantum chemical calculations of the ECD spectra, our synthesis allowed us to determine the absolute configuration (5S,7R) of the natural product (+)-raputindole D from the Rutaceous plant Raputia simulans. 相似文献
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Guanlin Li Ling Zhao Yicong Luo Youbin Peng Kai Xu Dr. Xiaohong Huo Prof. Dr. Wanbin Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(24):e202200273
Asymmetric desymmetrization has been demonstrated to be a powerful strategy for building stereocenters in asymmetric synthesis. Herein, a Pd/Cu catalyzed asymmetric desymmetrization reaction with a simple geminal dicarboxylate is reported. A wide scope of imino esters bearing an aryl or heteroaromatic group were compatible with this bimetallic catalytic system. The reactions proceeded smoothly, giving the desired products in good yields with high to excellent regio-, diastereo-, and enantioselectivity (up to 20 : 1 branched:linear, >20 : 1 dr, >99 % ee). Notably, the reaction favored branched selectivity, which is unusual for the Pd-catalyzed allylic alkylation reaction. In addition, the standard product could be easily transformed to other valuable molecules such as chiral allylic alcohols, carbamates, and organic boron compounds. Furthermore, DFT calculations were conducted to explain the origin of the branched selectivity. 相似文献
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Highly Enantioselective Construction of Tricyclic Derivatives by the Desymmetrization of Cyclohexadienones 下载免费PDF全文
Sandra del Pozo Dr. Alejandro Parra Dr. Sergio Díaz‐Tendero Dr. Rubén Mas‐Ballesté Dr. Silvia Cabrera Dr. José Alemán 《Angewandte Chemie (International ed. in English)》2014,53(31):8184-8189
The asymmetric synthesis of tricyclic compounds by the desymmetrization of cyclohexadienones is presented. The reaction tolerated a large variety of substituents at different positions of the cyclohexadienone, and heterocyclic rings of different sizes were accessible. Density functional theory calculations showed that the reaction proceeds through an asynchronous [4+2] cycloaddition. 相似文献
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Qi Teng Wenxiu Mao Dong Chen Zhen Wang Chen‐Ho Tung Zhenghu Xu 《Angewandte Chemie (International ed. in English)》2020,59(6):2220-2224
A rhodium(I)‐BINAP‐catalyzed highly enantioselective [2+2+2] cycloaddition of enynes with alkynes has been developed. Diverse fused tricyclic hydronaphthofuran scaffolds with three consecutive stereogenic centers were constructed in one step from easily available materials with excellent chemo‐, regio‐, diastereo‐, and enantioselectivity. Notable features of these reactions include 100 % atom economy, very broad scope, and mild reaction conditions. 相似文献
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Copper‐Catalyzed Enantioselective Arylative Desymmetrization of Prochiral Cyclopentenes with Diaryliodonium Salts 下载免费PDF全文
Dr. Hua Wu Dr. Qian Wang Prof. Dr. Jieping Zhu 《Angewandte Chemie (International ed. in English)》2018,57(10):2721-2725
A copper‐catalyzed enantioselective arylative desymmetrization of prochiral cyclopentenes with diaryliodonium salts was developed. In the presence of a catalytic amount of a chiral copper–bisoxazoline complex, which was generated in situ, the reaction of 4‐substituted or 4,4‐disubstituted cyclopent‐1‐enes with diaryliodonium hexafluoroarsenates afforded the chiral arylated products in good yields with excellent enantioselectivity. A cyclohexyl‐containing Box ligand was essential for the high enantioselectivity. Transformation of the enantiomerically enriched adducts into other chiral building blocks is also documented. 相似文献
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Dr. María D. Díaz‐de‐Villegas Dr. José A. Gálvez Dr. Ramón Badorrey Dr. M. Pilar López‐Ram‐de‐Víu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(44):13920-13935
Desymmetrization of diols is a powerful tool to the synthesis of chiral building blocks. Among the different approaches to perform discrimination between both enantiotopic hydroxyl groups, the organocatalytic approach has gained importance in the last years. A diverse range of organocatalysts has been used to efficiently promote this enantioselective transformation and this Minireview examines the different contributions in this field. 相似文献
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