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1.
Asymmetric Michael Addition/Intramolecular Cyclization Catalyzed by Bifunctional Tertiary Amine–Squaramides: Construction of Chiral 2‐Amino‐4H‐chromene‐3‐Carbonitrile Derivatives
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The efficient asymmetric Michael addition/intramolecular cyclization of malononitrile with dienones catalyzed by a chiral bifunctional tertiary amine–squaramide catalyst for the synthesis of chiral 2‐amino‐4H‐chromene‐3‐carbonitrile derivatives was developed. The corresponding products were obtained in good to excellent yields (up to 99 %) with excellent enantioselectivities (up to 98 % ee) for most of the bisarylidenecyclopentanones. 相似文献
2.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(31):9335-9338
An enantioselective C−H addition to a C=C bond represents the most atom‐efficient route for the construction of chiral carbon–carbon skeletons, a central research topic in organic synthesis. We herein report the enantioselective yttrium‐catalyzed C(sp3)−H bond addition of 2‐methyl azaarenes, such as 2‐methyl pyridines, to various substituted cyclopropenes and norbornenes. This process efficiently afforded a new family of chiral pyridylmethyl‐functionalized cyclopropane and norbornane derivatives in high yields and high enantioselectivities (up to 97 % ee ). 相似文献
3.
Bei‐Bei Zhan Lei Wang Jun Luo Xu‐Feng Lin Bing‐Feng Shi 《Angewandte Chemie (International ed. in English)》2020,59(9):3568-3572
A simple and ubiquitously present group, free amine, is used as a directing group to synthesize axially chiral biaryl compounds by PdII‐catalyzed atroposelective C?H olefination. A broad range of axially chiral biaryl‐2‐amines can be obtained in good yields with high enantioselectivities (up to 97 % ee). Chiral spiro phosphoric acid (SPA) proved to be an efficient ligand and the loading could be reduced to 1 mol % without erosion of enantiocontrol in gram‐scale synthesis. The resulting axially chiral biaryl‐2‐amines also provide a platform for the synthesis of a set of chiral ligands. 相似文献
4.
Asymmetric Ruthenium‐Catalyzed Hydrogenation of 2,6‐Disubstituted 1,5‐Naphthyridines: Access to Chiral 1,5‐Diaza‐cis‐Decalins
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Jianwei Zhang Fei Chen Yan‐Mei He Prof. Dr. Qing‐Hua Fan 《Angewandte Chemie (International ed. in English)》2015,54(15):4622-4625
The first asymmetric hydrogenation (AH) of 2,6‐disubstituted and 2,3,6‐trisubstituted 1,5‐naphthyridines, catalyzed by chiral cationic ruthenium diamine complexes, has been developed. A wide range of 1,5‐naphthyridine derivatives were efficiently hydrogenated to give 1,2,3,4‐tetrahydro‐1,5‐naphthyridines with up to 99 % ee and full conversions. This facile and green protocol is applicable to the scaled‐up synthesis of optically pure 1,5‐diaza‐cis‐decalins, which have been used as rigid chelating diamine ligands for asymmetric synthesis. 相似文献
5.
Asymmetric Ring Opening/Cyclization/Retro‐Mannich Reaction of Cyclopropyl Ketones with Aryl 1,2‐Diamines for the Synthesis of Benzimidazole Derivatives
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Yong Xia Dr. Lili Lin Fenzhen Chang Yuting Liao Prof. Dr. Xiaohua Liu Prof. Dr. Xiaoming Feng 《Angewandte Chemie (International ed. in English)》2016,55(40):12228-12232
A highly efficient asymmetric ring‐opening/cyclization/retro‐Mannich reaction of cyclopropyl ketones with aryl 1,2‐diamines has been realized using a chiral N,N′‐dioxide/ScIII catalyst. Benzimidazoles containing chiral side chains were generated under mild reaction conditions in excellent outcomes (up to 99 % yield and 97 % ee). This method also provides efficient access to chiral benzimidazole‐substituted amide and cycloheptene derivatives. 相似文献
6.
Min Liu Xing‐Wen Sun Dr. Ming‐Hua Xu Prof. Dr. Guo‐Qiang Lin Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(39):10217-10224
An efficient and convenient α‐hydroxyallylation approach for the asymmetric synthesis of a variety of β‐amino‐α‐vinyl alcohols has been successfully developed. A wide range of vinylic amino alcohol derivatives could be obtained in very good yields and with excellent diastereomeric ratios of up to 99:1 in favor of anti isomers by highly diastereoselective Zn‐promoted benzoyloxyallylation of chiral N‐tert‐butanesulfinyl imines with 3‐bromopropenyl benzoate at room temperature. In particular, excellent enantioinduction of the two new stereogenic centers was observed, with up to 98 % ee. The method provides a new route for the direct α‐hydroxyallylation of imines in a highly stereoselective manner. Moreover, the synthetic value of the method has also been demonstrated by the most concise and straightforward synthesis of (?)‐cytoxazone yet reported. 相似文献
7.
Jin‐Miao Tian Ai‐Fang Wang Ju‐Song Yang Xiao‐Jing Zhao Yong‐Qiang Tu Shu‐Yu Zhang Zhi‐Min Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(32):11139-11143
A novel chiral 1,5‐N,N‐bidentate ligand based on a spirocyclic pyrrolidine oxazoline backbone was designed and prepared, and it coordinates CuBr in situ to form an unprecedented catalyst that enables efficient oxidative cross‐coupling of 2‐naphthols. Air serves as an external oxidant and generates a series of C1‐symmetric chiral BINOL derivatives with high enantioselectivity (up to 99 % ee) and good yield (up to 87 %). This approach is tolerant of a broader substrates scope, particularly substrates bearing various 3‐ and 3′‐substituents. A preliminary investigation using one of the obtained C1‐symmetric BINOL products was used as an organocatalyst, exhibiting better enantioselectivity than the previously reported organocatalyst, for the asymmetric α‐alkylation of amino esters. 相似文献
8.
An efficient enantioselective cascade sulfa‐Michael/Michael addition reaction of trans‐3‐(2‐mercaptophenyl)‐2‐propenoic acid ethyl ester with nitroalkenes catalyzed by a chiral squaramide catalyst was disclosed. This cascade reaction afforded thiochroman derivatives with three contiguous stereocenters in high yields (up to 94%), excellent diastereoselectivities (up to >25:1 dr) and enantioselectivities (up to 99% ee). 相似文献
9.
Synthesis of β‐Substituted γ‐Aminobutyric Acid Derivatives through Enantioselective Photoredox Catalysis
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Jiajia Ma Jiahui Lin Lifang Zhao Dr. Klaus Harms Michael Marsch Dr. Xiulan Xie Prof. Dr. Eric Meggers 《Angewandte Chemie (International ed. in English)》2018,57(35):11193-11197
β‐Substituted chiral γ‐aminobutyric acids feature important biological activities and are valuable intermediates for the synthesis of pharmaceuticals. Herein, an efficient catalytic enantioselective approach for the synthesis of β‐substituted γ‐aminobutyric acid derivatives through visible‐light‐induced photocatalyst‐free asymmetric radical conjugate additions is reported. Various β‐substituted γ‐aminobutyric acid analogues, including previously inaccessible derivatives containing fluorinated quaternary stereocenters, were obtained in good yields (42–89 %) and with excellent enantioselectivity (90–97 % ee). Synthetically valuable applications were demonstrated by providing straightforward synthetic access to the pharmaceuticals or related bioactive compounds (S)‐pregabalin, (R)‐baclofen, (R)‐rolipram, and (S)‐nebracetam. 相似文献
10.
Tetsuya Yamada Hiroyoshi Noguchi Yuuya Nagata Michinori Suginome 《Journal of polymer science. Part A, Polymer chemistry》2010,48(4):898-904
Optically active chiral organonickel complexes served as efficient chiral initiators for living aromatizing polymerization of 1,2‐diisocyanobenzene derivatives, which afford optically active helical poly(quinoxaline‐2,3‐diyl)s up to 84% s.e. (screw‐sense excess). In comparison with asymmetric polymerization with the corresponding organopalladium initiators, the nickel initiators show a much greater polymerization rate, while the selectivity remains high. The organonickel initiators can be generated in situ from nickel(0) precursors with the corresponding enantiopure (S,S)‐2‐(4,5‐diphenylimidazolin‐2‐yl)phenyl chloride, leading to the convenient synthesis of highly stereo‐controlled poly(quinoxaline‐2,3‐diyl)s. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 898–904, 2010 相似文献
11.
An efficient and convenience method has been developed via a one‐pot double Mannich type reaction for the synthesis of the important chiral s‐triazole derivatives: (S)‐3‐α‐phenylethyl‐2,4‐dihydro‐5‐aryl‐oxymethyl‐1,2,4‐triazolo [3,4‐b] ‐1,3,5 ‐thiadiazines. 相似文献
12.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(42):13287-13291
The first enantioselective conjugate addition of silyl ketene imines to in situ generated indol‐2‐ones was performed in the presence of a chiral N ,N ′‐dioxide/NiII catalyst. This method provides efficient access to chiral β‐alkyl nitriles bearing congested vicinal all‐carbon quaternary stereocenters in up to 90 % yield with 23:1 d.r. and 98 % ee . The products enable facile transformations to chiral pyrroloindoline frameworks and spirocyclohexane oxindole derivatives. A possible transition state was also proposed to explain the origin of the asymmetric induction. 相似文献
13.
Yawen Hu Jianzhong Chen Bowen Li Zhenfeng Zhang Ilya D. Gridnev Wanbin Zhang 《Angewandte Chemie (International ed. in English)》2020,59(13):5371-5375
Earth‐abundant nickel, coordinated with a suitable chiral bisphosphine ligand, was found to be an efficient catalyst for the asymmetric hydrogenation of 2‐amidoacrylates, affording the chiral α‐amino acid esters in quantitative yields and excellent enantioselectivity (up to 96 % ee). The active catalyst component was studied by NMR and HRMS, which helped us to realize high catalytic efficiency on a gram scale with a low catalyst loading (S/C=2000). The hydrogenated products could be simply converted into chiral α‐amino acids, β‐amino alcohols, and their bioactive derivatives. Furthermore, the catalytic mechanism was investigated using deuterium‐labeling experiments and computational calculations. 相似文献
14.
Isamu Shiina Kenya Nakata Keisuke Ono Teruaki Mukaiyama 《Helvetica chimica acta》2012,95(10):1891-1911
Pyridine‐3‐carboxylic anhydride (3‐PCA) was found to function as an efficient coupling reagent for the preparation of carboxylic esters from various carboxylic acids with alcohols under mild conditions by a simple experimental procedure. This novel condensation reagent 3‐PCA was applicable not only for the synthesis of achiral carboxylic esters catalyzed by 4‐(dimethylamino)pyridine (DMAP) but also for the production of chiral carboxylic esters by the combination of chiral nucleophilic catalyst, such as tetramisole (=2,3,5,6‐tetrahydro‐6‐phenylimidazo[2,1‐b][1,3]thiazole) derivatives. An efficient kinetic resolution of racemic benzylic alcohols with achiral carboxylic acids was achieved by using 3‐PCA in the presence of (R)‐benzotetramisole ((R)‐BTM), and a variety of optically active carboxylic esters were produced with high enantiomeric excesses by this new chiral induction system without using a tertiary amine. 相似文献
15.
Chengxi Li Feng Wan Yuan Chen Henian Peng Wenjun Tang Shu Yu J. Christopher McWilliams Jason Mustakis Lacey Samp Robert J. Maguire 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(38):13707-13717
We herein report the development of a conformationally defined, electron‐rich, C2‐symmetric, P‐chiral bisphosphorus ligand, ArcPhos, by taking advantage of stereoelectronic effects in ligand design. With the Rh‐ArcPhos catalyst, excellent enantioselectivities and unprecedentedly high turnovers (TON up to 10 000) were achieved in the asymmetric hydrogenation of aliphatic carbocyclic and heterocyclic tetrasubstituted enamides, to generate a series of chiral cis‐2‐alkyl‐substituted carbocyclic and heterocyclic amine derivatives in excellent enantiomeric ratios. This method also enabled an efficient and practical synthesis of the Janus kinase inhibitor (R)‐tofacitinib. 相似文献
16.
Jie Chen Pan Guo Jianguo Zhang Jiaxin Rong Wangbin Sun Yaojia Jiang Teck‐Peng Loh 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(36):12804-12809
An efficient RhII‐catalyzed synthesis of functionalized α‐vinyl aldehydes with high E/Z stereoselectivity was developed. The reaction mediates the cyclopropanation of enaminones with vinyl carbenoids that are generated from cyclopropenes in situ to give the aminocyclopropane intermediates. Selective C?C bond cleavage of the cyclopropane intermediates leads to formation of α‐vinyl aldehyde derivatives with high E/Z selectivity. This method proceeds at room temperature under very mild reaction conditions and works with a broad substrate scope. 相似文献
17.
Feng‐Tao Sheng Zhi‐Min Li Yi‐Zhu Zhang Li‐Xing Sun Yu‐Chen Zhang Wei Tan Feng Shi 《中国化学》2020,38(6):583-589
An atroposelective synthesis of a new class of 3,3’‐bisindoles bearing axial and central chirality has been established via catalytic asymmetric addition reactions using isatin‐derived imines as electrophiles (23 examples, up to 80% yield, > 95 : 5 dr, 98 : 2 er). This approach takes advantage of chiral phosphoric acid‐catalyzed dynamic kinetic resolution of 2‐substituted 3,3’‐bisindoles via nucleophilic addition of such substrates with isatin‐derived imines. In this approach, isatin‐derived imines acted as a class of competent electrophiles due to their high reactivity and bulky size, which provided an easy access to axially chiral 3,3'‐bisindoles incorporated with a biologically important chiral 3‐aminooxindole unit. This approach has greatly expanded the generality and applicability of the strategy of dynamic kinetic resolution for the synthesis of enantioenriched 3,3’‐bisindole derivatives bearing both axial and central chirality. 相似文献
18.
Xiao‐Lei An Dr. Jia‐Rong Chen Dr. Chang‐Feng Li Fu‐Gen Zhang You‐Quan Zou Dr. Ying‐Cen Guo Prof. Dr. Wen‐Jing Xiao 《化学:亚洲杂志》2010,5(10):2258-2265
The scope of the novel ruthenium‐catalyzed tandem cross‐metathesis/intramolecular‐hydroarylation sequence is described. This methodology offers a practical and efficient synthesis of structurally diverse and complex tetrahydrocarbazoles in good to excellent yields (up to 98 %). Moreover, preliminary efforts towards the development of an enantioselective version of the current process by sequential catalysis with ruthenium complex and chiral amine are presented, with high yields and enantioselectivities (up to 88 % yield and 91 % ee). 相似文献
19.
Lei Zhou Qi Shuai Huan‐feng Jiang Chao‐Jun Li Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(43):11668-11674
A simple and efficient method for the synthesis of γ,δ‐alkynyl‐β‐amino acid derivatives by a copper‐catalyzed three‐component amine–alkyne–alkyne addition reaction was developed. Various γ,δ‐alkynyl‐β‐amino acid derivatives were synthesized in moderate to good yields in one step. With chiral prolinol derivatives employed as the amine component, excellent diastereoselectivities (up to >99:1 diastereomeric ratio (dr)) were obtained. The scope of the reaction and further transformations of the resulting amino acid derivatives, such as deprotection and cyclization are also described. 相似文献
20.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(11):3101-3104
A ligand‐promoted catalytic [4+2] annulation reaction using indole derivatives and donor‐acceptor (D‐A) cyclobutanes is reported, thus providing an efficient and atom‐economical access to versatile cyclohexa‐fused indolines with excellent levels of diastereoselectivity and a broad substrate scope. In the presence of a chiral SaBOX ligand, excellent enantioselectivity was realized with up to 94 % ee. This novel synthetic method is applied as a general protocol for the total synthesis of (±)‐akuammicine and the formal total synthesis of (±)‐strychnine from the same common‐core scaffold. 相似文献