Article
Chemistry, Organic
Linlong Dai, Qiaohong Zhu, Jie Zeng, Yuheng Liu, Guofu Zhong, Xiaoyu Han, Xiaofei Zeng
Summary: The study presents an effective strategy for the synthesis of chiral imidazolidines through catalytic reactions, achieving high yields and enantioselectivities. Additionally, this method can also be applied in the synthesis of chiral vicinal diamines by adjusting the reaction conditions.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Haruna Araki, Shohei Furuya, Kazuya Kanemoto, Shin-ichi Fukuzawa
Summary: The conjugated addition reaction of 1-pyrroline-5-carbonitrile to alpha-enones was effectively catalyzed by AgF/ThioClickFerrophos (TCF) in diethyl ether in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and nearly single diastereomers of adducts with good enantiomeric excesses (up to 97% ee) were obtained in high yields. The reduction of the nitrile group with H2/Raney Ni in ethanol successfully transformed the conjugate adduct to the corresponding spirocyclic piperidine (60% yield) as a single stereoisomer.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Houda Gazzeh, Fadwa Rouatbi, Sami Chniti, Moheddine Askri, Michael Knorr, Carsten Strohmann, Christopher Golz, Al Mokhtar Lamsabhi
Summary: The mechanism of a three-component one-pot cycloaddition reaction was studied using both theoretical and experimental methods. The reactivity difference between the unsymmetrical exocyclic dienones was analyzed to explain the observed regio- and stereoselectivity, and the results were confirmed by calculations. The reaction proceeded under kinetic control and showed chemoselectivity, producing two highly diastereomerically enriched compounds. The intermolecular hydrogen bonding and optical properties of the products were also investigated.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Zhigang Chen, Wei Zhong, Sihua Liu, Ting Zou, Kaiqiang Zhang, Chuliang Gong, Wenyan Guo, Feizhi Kong, Libo Nie, Shunqin Hu, Haifei Wang
Summary: In this study, we report the highly diastereo- and enantioselective [3 + 2] cycloadditions of iminoesters with various alpha-substituted acrylates. The reactions are catalyzed by AgHMDS/DTBM-Segphos or Ag2O/CA-AA-Amidphos, and result in the stereodivergent synthesis of chiral C4-ester-quaternary exo- or endo-pyrrolidines with high yields and excellent diastereo- and enantioselectivities (up to >99:1 dr and >99% ee). The gram-scale synthetic exo-adduct is particularly significant, as it enables the total synthesis of the spirotryprostatin A alkaloid in nine steps with a 36% overall yield.
Article
Chemistry, Organic
Mamta Gill, Arko Das, Vinod K. Singh
Summary: An enantioselective (3+2) cycloaddition reaction has been reported for the synthesis of chiral polysubstituted pyrrolidines. The reaction displays opposite regioselectivity with excellent enantioselectivities and yields. Interestingly, changing the alpha-substituents of the iminoesters results in the formation of normal (3+2) cycloaddition products with excellent enantioselectivities as well.
Article
Chemistry, Organic
Jose Cortes Vazquez, Jacqkis Davis, Vladimir N. Nesterov, Hong Wang, Weiwei Luo
Summary: A formal [3 + 3] cyclization reaction has been developed for the synthesis of 1,3,4-oxadiazinanes with generally high yields (up to 96%). The reaction, catalyzed by Sc(OTf)(3), has a broad substrate scope for both diaziridines and quinones. The synergistic activation of 1,3-dipolar diaziridines and dipolar quinones was found to be essential for enabling this reaction.
Article
Chemistry, Organic
Zhenjie Gan, Ke Li, Hui Zhang, Er-Qing Li
Summary: A highly efficient copper/GanPhos-catalyzed 1,3-dipolar cycloaddition of azomethine ylides is reported in this study, providing optically active spiro[dihydronaphthalene-2,3'-pyrrolidine]s with one spiro quaternary and three tertiary stereogenic centers in good yields and high ee values. This protocol demonstrates high diastereo- and enantioselectivity, broad substrate scope, and mild reaction conditions.
SYNTHESIS-STUTTGART
(2021)
Article
Biochemistry & Molecular Biology
Eduardo Garcia-Minguens, Marcos Ferrandiz-Saperas, M. de Gracia Retamosa, Carmen Najera, Miguel Yus, Jose M. Sansano
Summary: This study investigated the enantioselective 1,3-dipolar cycloaddition between (Z)-nitroalkenes bearing a masked amino group in the beta-position and imino esters, using various chiral ligands and silver salts. The absolute configuration of the reaction products was determined through NMR experiments and electronic circular dichroism (ECD), leading to the generation of the corresponding cis-2,3-diaminoprolinate in excellent enantiomeric ratio.
Article
Chemistry, Applied
Kai-Kai Wang, Yan-Li Li, Rong-Xiang Chen, Ai-Li Sun, Zhan-Yong Wang, Ying-Chao Zhao, Ming-Yue Wang, Shi Sheng
Summary: The additive-free 1,3-dipolar cycloaddition reaction enables diversity-oriented synthesis of novel and structurally complex derivatives in high yields and excellent diastereoselectivities.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Zalina T. Gugkaeva, Maria Panova, Alexander F. Smol'yakov, Michael G. Medvedev, Alan T. Tsaloev, Ivan A. Godovikov, Victor Maleev, Vladimir A. Larionov
Summary: We have developed a protocol for asymmetric synthesis of artificial amino acids with a 3-spiropyrrolidine oxindole skeletal structure containing continuous tetrasubstituted carbon stereocenters. This synthesis is achieved through a 1,3-dipolar cycloaddition reaction of azomethine ylides generated in situ with a chiral dehydroalanine Ni(II) complex. The reaction of the Ni(II) complex with isatins and amino acids in ethanol solvent resulted in diastereomeric complexes with high selectivities. Quantum chemical calculation explained the formation of different regioisomers for sarcosine and proline. The acidic decomposition of Ni(II) complexes yielded the desired unnatural complex amino acids, and the chiral auxiliary ligand could be recovered and reused for subsequent reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Shohei Furuya, Kenji Muroi, Kazuya Kanemoto, Shin-ichi Fukuzawa
Summary: The stereodivergent asymmetric synthesis of 2,5-trans/cis pyrrolidines by 1,3-dipolar cycloaddition using two different types of activated alkenes is described. The reaction using ylidene-isoxazolones as dipolarophiles produced 2,5-trans pyrrolidines, while the reaction using acyclic enones as activated alkenes afforded 2,5-cis substituted pyrrolidines.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Mahzad Dehghany, Jennifer M. Schomaker
Summary: Silver offers a cost-effective alternative for asymmetric transformations of alkenes and alkynes, driving selectivity through non-covalent interactions. The reactions enable direct enantioselective transformations of the alkene/alkyne pi bond and functionalization at adjacent C-H bonds.
CURRENT OPINION IN GREEN AND SUSTAINABLE CHEMISTRY
(2021)
Article
Chemistry, Organic
Zhen-Hua Wang, Ji-Hong Liu, Yan-Ping Zhang, Jian-Qiang Zhao, Yong You, Ming-Qiang Zhou, Wen-Yong Han, Wei-Cheng Yuan
Summary: In this study, the enantioselective desymmetrization of N-arylmaleimides was achieved using a Cu(OTf)(2)/chiral ferrocenyl P,N-ligand complex as a catalyst, through the asymmetric 1,3-dipolar cycloaddition reaction of N-2,2,2-trifluoroethylisatin ketimines. A series of structurally diverse F3C-containing octahydropyrrolo[3,4-c]pyrroles, bearing four contiguous carbon stereocenters and one stereogenic chiral C-N axial bond, were obtained with excellent results (<= 99% yield, >20:1 dr, and 99% ee).
Article
Chemistry, Organic
Yabo Deng, Zhenghao Dong, Fengyun Gao, Yifei Guo, Mengmeng Sun, Yongzhen Li, Yalan Wang, Qushuo Chen, Kairong Wang, Wenjin Yan
Summary: An amino-controlled regiodivergent asymmetric synthesis of CF3-containing spiro-pyrrolidine-pyrazolone compounds is described, offering adducts in excellent yields, dr, and ee when using alkaloid-derived squaramide as the catalyst. Switching to cyclohexanediamine-derived squaramide led to the formation of a series of structural isomers through a switched umpolung reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yi-Nan Li, Xin Chang, Qi Xiong, Xiu-Qin Dong, Chun-Jiang Wang
Summary: The Cu-catalyzed endo-selective asymmetric 1,3-dipolar cycloaddition of azomethine ylides with ethenesulfonyl fluorides (ESFs) provides an efficient method to access a wide range of chiral pyrrolidine-3-sulfonyl fluorides and other chiral sulfonyl derivatives with good yields and stereoselectivity, demonstrating their synthetic utility in SuFEx chemistry.
CHINESE CHEMICAL LETTERS
(2021)
