Article
Chemistry, Physical
Peng-Fei Yang, Jian-Xing Liang, Han -Tong Zhao, Wei Shu
Summary: In this study, a straightforward method to access enantioenriched 1,n-diamines containing a chiral alpha-branched aliphatic amine is achieved through Ni-catalyzed asymmetric hydroamination. This method delivers good yields and excellent enantioselectivities with diverse substitution patterns, and exhibits excellent functional group tolerance.
Article
Chemistry, Multidisciplinary
Sourav Dutta, Arka Porey, Joyram Guin
Summary: Here, we present an efficient strategy for the enantioselective synthesis of oxindoles with a C3-quaternary stereocenter using N-heterocyclic carbene (NHC) catalyzed desymmetrization of diols. The process involves the catalytic asymmetric transfer acylation of primary alcohols using readily available aldehydes. This reaction provides easy access to diverse C3-quaternary oxindoles with excellent enantioselectivity. The synthetic potential of the process is demonstrated through the preparation of key intermediates for (-)-esermethole and (-)-physostigmine.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Hui Sun, Huijian Shang, Bin Cui
Summary: Asymmetric catalysis using a chiral (Salen)Mn(III) complex has been successfully applied to highly enantioselective intramolecular haloamination reactions of alkenes. Experimental results suggest that the polarization of the C5-C6 bond has a significant effect on the regioselectivity of the products.
Article
Chemistry, Organic
Zhiqiang Zhou, Dongyang Xu, Wei Jiang, Junhan Chen, Yanxia Zhen, Jiyou Huo, Jiahang Yan, Jinming Gao, Weiqing Xie
Summary: In this study, a catalytic asymmetric intramolecular vinylogous aldol reaction using dual organocatalysts was described, allowing for the convergent synthesis of ortho-fused tricyclic diketones with excellent enantioselectivities and diastereoselectivities. Notably, the reaction selectively generates three consecutive stereogenic carbon centers, including a quaternary one. Density functional theory calculations revealed that the enhanced enantioselectivity was facilitated by a transannular hydrogen bonding between the protonated quinuclidine moiety of the chiral aminocatalyst and the diketone fragment of the substrate.
Article
Chemistry, Organic
Lei Cao, Xing-Ping Zhang, Ming-Sheng Xie, Hai-Ming Guo
Summary: A CuI-catalyzed C-N coupling reaction between 3-bromoDMAP and L-prolinamides was carried out under 80°C for 12-16 hours, where the structure of prolinamide exerted an accelerating effect on the Ullmann type reaction. This reaction was utilized for the construction of chiral 3-amino DMAP catalysts. Moreover, enantioenriched DMAP analogue C8 was applied in an asymmetric Black rearrangement of 2-benzofuranylcarbonates, leading to the formation of 3,3-disubstituted benzofuran-2-ones with up to 96% yield and 97% ee.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Zachary P. Sercel, Alexander W. Sun, Brian M. Stoltz
Summary: Enantioenriched gem-disubstituted 4-imidazolidinones were prepared in high yield and high enantioselectivity through Pd-catalyzed decarboxylative asymmetric allylic alkylation. A rapid synthetic route starting from 2-thiohydantoin was developed, and the orthogonality of the protecting groups used for nitrogen-rich products was demonstrated, indicating potential applications in drug design.
Article
Chemistry, Organic
Ricardo Molina Betancourt, Phannarath Phansavath, Virginie Ratovelomanana-Vidal
Summary: Enantioenriched cis-3-fluoro-chroman-4-ol derivatives were conveniently prepared through ruthenium-catalyzed asymmetric transfer hydrogenation using a dynamic kinetic resolution process. The reaction proceeded under mild conditions, affording the reduced fluorinated alcohols in good yields, high diastereomeric ratios, and excellent enantioselectivities.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Lu Xiao, Bo Li, Fan Xiao, Cong Fu, Liang Wei, Yanfeng Dang, Xiu-Qin Dong, Chun-Jiang Wang
Summary: This study reports an efficient catalytic asymmetric formal 1,3-dipolar cycloaddition reaction for the construction of azepino[3,4,5-cd]-indoles fused with a challenging seven-membered N-heterocycle. The full stereodivergence of this transformation was established via synergistic catalysis followed by acid-promoted epimerization, which allows predictable access to multiple stereoisomers.
Article
Chemistry, Multidisciplinary
Dattatraya H. Dethe, Vimlesh Kumar, Manmohan Shukla
Summary: Here, we report the first palladium/MPAA catalyzed enantioselective C-H activation/[4 + 1] annulation of diarylmethyltriflamide and olefins to construct chiral cis-1,3-disubstituted isoindoline derivatives. The use of a readily accessible mono-N-protected amino acid as a chiral ligand improves the efficiency and enantioselectivity of the catalytic transformation, enabling the synthesis of both enantiomers of the product.
Article
Chemistry, Organic
Travis Menard, Aragorn Laverny, Scott E. Denmark
Summary: This method describes the catalytic, enantioselective carbosulfenylation of alkenes to construct difficult-to-generate, enantioenriched, 3,4-disubstituted chromans with moderate to high yields and excellent enantioselectivities. The resulting thioether moiety is amenable to various functional group manipulations and transformations, providing access to sulfur-containing functional groups present in natural products and pharmaceuticals.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Zhen-Sheng Jia, Yong-Jie Wu, Qi-Jun Yao, Xue-Tao Xu, Kun Zhang, Bing-Feng Shi
Summary: A Pd-catalyzed atroposelective C-H allylation with 1,1-disubstituted alkenes was carried out using the chiral ligand L-pGlu-OH, resulting in the synthesis of enantioenriched N-aryl peptoid atropisomers. High yields and excellent enantioselectivities were achieved, with up to 90% yield and 97% ee.
Article
Chemistry, Organic
Fu-Yu Li, Bei Wang, Hong Xu, Yao Xiao, Dong-Wei Huang, Ji-Yu Wang
Summary: The convenient synthesis of diverse and complex poly-substituted beta-alkenyl valerolactones is achieved through Fe(iii)-catalyzed reduction radical tandem strategy of 2,3-dienoates and allyl alcohols. The allyl alcohols can undergo simultaneous transformations into alkyl radicals and allyl ester intermediates under Fe(iii) catalysis, which then react via Michael addition to form the desired products. Notably, this method also enables the preparation of spiro-valerolactones and cyclo-valerolactones, as well as the transformation of beta-alkenyl valerolactones into previously unreported pyrazole lactone compounds.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Physical
Shengzu Duan, Ailin Pan, Ya Du, Guanlin Zhu, Xun Tian, Hongbin Zhang, Patrick J. Walsh, Xiaodong Yang
Summary: A Ni/(S,S)-BenzP* catalyst system was developed for the asymmetric synthesis of branched a-aminophosphine oxides through an enantioselective Markovnikov addition of H-phosphine oxides to 2-azadienes. Various readily available 2-azadienes and H-phosphine oxides showed high enantioselectivities (up to 99%) and good yields (up to 96%). The synthesized chiral a-aminophosphine oxides serve as important building blocks for the synthesis of bioactive compounds, organocatalysts, and ligands.
Article
Chemistry, Organic
Qiaoyu Chen, Sanliang Li, Xiaoxiao Xie, Hao Guo, Junfeng Yang, Junliang Zhang
Summary: A Pd/Xu-Phos-catalyzed asymmetric Heck/Suzuki domino reaction has been developed, demonstrating high functional group tolerance and the ability to couple with various aryl/alkenyl borates. A series of chiral disubstituted dihydroisoquinolinones were obtained in good yields and excellent enantioselectivities.
Article
Chemistry, Organic
Yang-Guang Chen, Heng-Bin Yu, Yin Tian, Cheng Peng, Ming-Sheng Xie, Hai-Ming Guo
Summary: A chiral 4-aryl-pyridine-N-oxide nucleophilic organocatalyst was used to efficiently synthesize chiral phthalidyl ester prodrugs via acylative dynamic kinetic resolution process. The phthalidyl esters were produced with up to 97% yield and 97% ee at room temperature using the 3,5-dimethylphenyl-derived ArPNO catalyst. Two phthalidyl esters of prodrugs, talosalate and talmetacin, were successfully generated. An acyl transfer mechanism was proposed based on control experiments and density functional theory calculations.
