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1.
Novel axially chiral N‐heterocyclic carbene (NHC) Pd(II) complexes were prepared from optically active 1,1′‐binaphthalenyl‐2,2′‐diamine (BINAM) and H8‐BINAM and their crystal structures were unambiguously determined by X‐ray diffraction. These chiral N‐heterocyclic carbene (NHC) Pd(II) complexes were applied in the oxidative kinetic resolution of secondary alcohols using molecular oxygen as a terminal oxidant or under aerobic conditions, affording the corresponding sec‐alcohols in good yields with moderate to good enantioselectivities. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
2.
[reaction: see text] Axially chiral N-heterocyclic carbene (NHC) Pd(II) complexes were prepared from optically active 1,1'-binaphthalenyl-2,2'-diamine (BINAM) and H8-BINAM and applied in the oxidative kinetic resolution of secondary alcohols using molecular oxygen as a terminal oxidant. The corresponding sec-alcohols can be obtained in good yields with moderate to good enantioselectivities. 相似文献
3.
The first nonenzymatic kinetic resolution of β-lactams has been achieved. Alcoholysis of their N-aroyl derivatives in the presence of a simple chiral acyl transfer catalyst, benzotetramisole, produces β-amino acid derivatives with excellent enantioselectivity. 相似文献
4.
Yingwei Wang Guangxun Li Hongxin Liu Zhuo Tang Yuan Cao Gang Zhao 《Tetrahedron letters》2017,58(30):2993-2996
We have developed a highly efficient and practical strategy for the kinetic resolution of indoline derivatives, involving a chiral Brønsted acid-catalyzed iminium ion formation and asymmetric transfer hydrogenation cascade process. The kinetic resolution allows the synthesis of 2-substituted N-benzylindolines in good yields with moderate to excellent enantioselectivities. 相似文献
5.
During the past decade, the chemistry of BINAP, BINAM, and BINOL derivatives experienced an important development due to multiple applications in catalysis, metallo-supramolecular chemistry and material science. Consequently, the need to develop functionalized binaphthyl derivatives became crucial. In this context, we were interested in preparing 2,2′-dimethoxy-1,1′-binaphthyl-3,3′-diacetic acid species. The latter were efficiently prepared using a modified Arndt-Eistert reaction that afforded the expected chiral diacid in good yield. Compared to the method we described earlier, this new strategy allows the preparation of the target homologated diacid chloride in a very efficient manner, limiting wastes and tedious column chromatographies. 相似文献
6.
Hyung-Joon Kang Changseok Lee Prof. Dr. Sungwoo Hong 《Angewandte Chemie (International ed. in English)》2023,62(24):e202305042
Kinetic resolution is a powerful strategy for the isolation of enantioenriched compounds from racemic mixtures, and the development of selective catalytic processes is an active area of research. Here, we present a nickel-catalyzed kinetic resolution of racemic α-substituted unconjugated carbonyl alkenes via the enantio-, diastereo-, and regioselective hydroamination. This protocol affords both chiral α-substituted butenamides and syn-β2,3-amino acid derivatives with high enantiomeric purity (up to 99 % ee) and selectivity factor up to >684. The key to the excellent kinetic resolution efficiency is the distinctive architecture of the chiral nickel complex, which enables successful resolution and enantioselective C−N bond construction. Mechanistic investigations reveal that the unique structure of the chiral ligand facilitates a rapid migratory insertion step with one enantiomer. This strategy provides a practical and versatile approach to prepare a wide range of chiral compounds. 相似文献
7.
Yong Sun Park 《Tetrahedron: Asymmetry》2009,20(21):2421-2427
Recent results on the chiral auxiliary-mediated dynamic resolution of α-halo acid derivatives in nucleophilic substitution have been outlined and classified into two major mechanistic categories, dynamic thermodynamic resolution (DTR) and dynamic kinetic resolution (DKR). Asymmetric nucleophilic substitution of α-halo acid derivatives with various nitrogen, oxygen, sulfur, and carbon nucleophiles is widely used for the stereoselective preparation of α-substituted carboxylic acids. 相似文献
8.
Kyoung Hoon Kim 《Tetrahedron》2004,60(41):9037-9042
Mono-N-alkylated octahydrobinaphthyl-2,2′-diamine (H8-BINAM) chiral ligands were employed in the catalytic and asymmetric oxidative coupling of methyl 3-hydroxy-2-naphthoate to the corresponding binaphthol derivative. The diamine ligand with one N-(3-pentyl) group shows highest enantioselectivity in the biaryl coupling among other BINAM derivatives, and the coupling reaction proceeds faster than the reactions using alkanediamine ligands. 相似文献
9.
Dr. Satoru Kuwano Yusei Hosaka Prof. Dr. Takayoshi Arai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(56):12920-12923
Chiral benzazaborole-catalyzed regioselective sulfonylations of unprotected carbohydrate derivatives have been developed. This methodology enables direct regioselective functionalization of the secondary OH group in carbohydrate in the presence of the primary OH group. By using the chiral organoboron catalysis, kinetic resolution of the carbohydrate derivatives was also achieved. 相似文献
10.
Catalytic Enantioselective Synthesis of Atropisomeric Biaryls: A Cation‐Directed Nucleophilic Aromatic Substitution Reaction
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Roly J. Armstrong Prof. Dr. Martin D. Smith 《Angewandte Chemie (International ed. in English)》2014,53(47):12822-12826
A catalytic enantioselective nucleophilic aromatic substitution reaction which yields axially chiral biaryl derivatives in excellent yields with e.r. values of up to 97:3 has been developed. This process uses a chiral counterion to direct the addition of thiophenolate to a prochiral dichloropyrimidine by a tandem desymmetrization/kinetic resolution mechanism. The products can be derivatized to a range of atropisomeric structures without any reduction in enantioenrichment, thus offering access to unexplored chiral biaryl architectures. 相似文献
11.
Wei Liu Qianwen Jiang Prof. Dr. Xiaoyu Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23804-23808
A versatile kinetic resolution of protecting-group-free BINAMs and NOBINs has been realized through chiral phosphoric acid catalyzed triazane formation with azodicarboxylates. A series of mono-N-protected and unprotected BINAMs, diphenyl diamines and NOBIN derivatives could be kinetically resolved with excellent performances (with s factor up to 420). The gram-scale reactions and facile derivatizations of the chiral products demonstrate the potential of these methods in the asymmetric synthesis of chiral catalysts and ligands. 相似文献
12.
13.
Samarium iodide-mediated cross-coupling of N-tosyl ferrocenylideneamine with planar chiral ferrocenecarboxaldehydes or benzaldehyde chromium complexes gave diastereoselectively the corresponding anti-beta-amino alcohol derivatives in good yields, while N-tosyl benzylideneamine produced syn-beta-amino alcohols by coupling with planar chiral arylaldehydes. Dynamic kinetic resolution of a configurationally equilibrated reactive species generated from achiral N-tosyl ferrocenilideneamine and benzylideneamine by reduction with samarium iodide was observed in the cross-coupling with planar chiral arylaldehydes giving both antipodes of beta-amino alcohols depending on the planar chirality. The obtained anti-beta-amino alcohol with the ferrocene ring was utilized as a chiral ligand for catalytic asymmetric reduction of acetophenone. 相似文献
14.
[reaction: see text] Samarium iodide mediated reductive cross-coupling of N-tosyl benzylideneamine with benzaldehydes or the corresponding chromium complexes gave syn-beta-amino alcohol derivatives. A dynamic kinetic resolution of a configurationally equilibrated reactive species occurred in the cross-coupling with planar chiral benzaldehyde chromium complexes. 相似文献
15.
Coldham I Dufour S Haxell TF Patel JJ Sanchez-Jimenez G 《Journal of the American Chemical Society》2006,128(33):10943-10951
Dynamic resolution has been studied as a method for the asymmetric synthesis of 2-substituted pyrrolidines. Highly enantioselective electrophilic substitutions of racemic 2-lithiopyrrolidines in the presence of a chiral ligand have been achieved. The organolithium compounds were prepared by tin-lithium exchange from the corresponding tributylstannanes and n-butyllithium or by deprotonation of N-(tert-butyloxycarbonyl)pyrrolidine with sec-butyllithium. A range of N-substituents and chiral ligands were investigated for the dynamic resolution. Electrophilic quench of the resolved diastereomeric 2-lithiopyrrolidine-chiral ligand complexes provided the enantiomerically enriched 2-substituted pyrrolidines. With N-alkyl derivatives, the resolution occurs conveniently at (or just below) room temperature and either enantiomer of the product can be formed by appropriate choice of the chiral ligand. The asymmetric induction occurs as a result of a thermodynamic preference for one of the diastereomeric complexes. The minor complex was found to have a faster rate of reaction with the electrophile. The use of N-allylic derivatives provides a means to prepare the N-unsubstituted pyrrolidine products. Best results were obtained with the N-2,3-dimethylbut-2-enyl derivative, and this N-substituent could be cleaved using 1-chloroethyl chloroformate. With N-Boc-2-lithiopyrrolidine, the enantioselectivity arises by a kinetic resolution and high levels of asymmetric induction in the presence of excess n-butyllithium can be obtained. Dynamic kinetic resolution of the N-Boc derivative is limited in the scope of electrophile that can be used. 相似文献
16.
Nakamura S Nakagawa R Watanabe Y Toru T 《Angewandte Chemie (International ed. in English)》2000,39(2):353-355
Too unstable for asymmetric deprotonation, alpha-sulfenyl carbanions can undergo asymmetric substitution reactions with high stereoselectivity [Eq. (1)]. The key to the asymmetric induction is the dynamic kinetic resolution of the complex formed between the organolithium compound and a chiral ligand, the most effective of which were bisoxazoline derivatives. 相似文献
17.
Everton Machado da Silva Hrika Danielle Almeida Vidal Marcelo Augusto Pereira Janurio Arlene Gonalves Corrêa 《Molecules (Basel, Switzerland)》2023,28(1)
BINOL derivatives have shown relevant biological activities and are important chiral ligands and catalysts. Due to these properties, their asymmetric synthesis has attracted the interest of the scientific community. In this work, we present an overview of the most efficient methods to obtain chiral BINOLs, highlighting the use of metal complexes and organocatalysts as well as kinetic resolution. Further derivatizations of BINOLs are also discussed. 相似文献
18.
Lu Wang Fei Li Xunhua Liu Guo Wei Yixiang Cheng Chengjian Zhu 《Journal of polymer science. Part A, Polymer chemistry》2013,51(19):4070-4075
A novel chiral (S)‐BINAM‐based fluorescent polymer sensor was designed and synthesized by the polymerization of 4,4′‐((2,5‐dibutoxy‐1,4‐phenylene)bis(ethyne‐2,1‐diyl))‐dibenzaldehyde ( M‐1 ) with (S)‐2,2′‐binaphthyldiamine (S‐BINAM, M‐2 ) via Schiff's base formation. The resulting helical chiral polymer sensor exhibited remarkable “turn‐on” bright blue fluorescence color upon the addition of trivalent metal ions under a commercially available UV lamp; this change can be clearly observed by the naked eye for direct visual discrimination at low concentration. More importantly, the addition of trivalent metal cations can lead to a most pronounced change of CD spectra of the chiral polymer indicating this kind chiral sensor can also be used as a sole probe for selective recognition of trivalent metal cations based on CD spectra. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4070–4075 相似文献
19.
A convenient method for the preparation of the hitherto unknown chiral alpha-methylene beta-lactam derivatives 5a,b is reported. The optically active alpha-methylene beta-lactams 5a-c, and their corresponding amino acids 6a-c have been readily made available through lipase-catalyzed kinetic resolution in high enantiomeric purity (up to 99% ee). The N-substituted beta-lactam derivatives 4a, b and 10 are not accepted by the lipases and were prepared in optically active form by chemical transformation. 相似文献
20.
Dr. Changgui Zhao Fangyi Li Prof. Dr. Jian Wang 《Angewandte Chemie (International ed. in English)》2016,55(5):1820-1824
The dynamic kinetic resolution of 6‐hydroxypyranones with enals or alkynals through an asymmetric redox esterification is catalyzed by a chiral N‐heterocyclic carbene. The resulting esters are obtained in good to high yields and with high levels of enantio‐ and diastereocontrol. The reaction products are further derivatized to obtain functionalized sugar derivatives and natural products. 相似文献