| Publication |
Sentence |
Publish Date |
Extraction Date |
Species |
| Zhenli Luo, Zhewei Li, Haoqiang Zhao, Ji Yang, Lijin Xu, Ming Lei, Qinghua Fan, Patrick Joseph Wals. Borane-Catalyzed Tandem Cyclization/Hydrosilylation Towards Enantio- and Diastereoselective Construction of trans-2,3-Disubstituted-1,2,3,4-Tetrahydroquinoxalines. Angewandte Chemie (International ed. in English). 2023-06-20. PMID:37338222. |
herein we report that a frustrated lewis pair-based catalyst generated via in situ hydroboration of 2-vinylnaphthalene with hb(c6f5)2 allows for the one-pot tandem cyclization/hydrosilylation of 1,2-diaminobenzenes and 1,2-diketones with commercially available phsih3 to exclusively afford trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines in high yields with excellent diastereoselectivities (>20:1 dr). furthermore, this reaction can be rendered asymmetric by using an enantioenriched borane-based catalyst derived from hb(c6f5)2 and a binaphthyl-based chiral diene to give rise to enantioenriched trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines in high yields with almost complete diastereo- and enantiocontrol (>20:1 dr, up to >99% ee). |
2023-06-20 |
2023-08-14 |
Not clear |
| Li-Xia Liu, Yu-Qing Bai, Xiang Li, Chang-Bin Yu, Yong-Gui Zho. Palladium-catalyzed asymmetric allenylic alkylation: construction of multiple chiral thiochromanone derivatives. Chemical science. vol 14. issue 20. 2023-05-26. PMID:37234894. |
herein, by the combination of base-promoted retro-sulfa-michael addition and palladium-catalyzed asymmetric allenylic alkylation, the streamlined synthesis of chiral thiochromanones containing two central chiralities (including a quaternary stereogenic center) and an axial chirality (allene unit) was successfully realized with up to 98% yield, 49.0 : 1 dr and >99% ee. |
2023-05-26 |
2023-08-14 |
Not clear |
| Jingxin Wang, Yongjie Shi, Fangyuan Wang, Fanping Huang, Shaotao Bai, Yu Zhao, Xumu Zhan. Concise Synthesis of Chiral Tricyclic Lactams by Tandem Dynamic Kinetic Asymmetric Reductive Amination/Lactamization Using Ammonium Salts. Angewandte Chemie (International ed. in English). 2023-04-22. PMID:37086028. |
this ru-catalyzed system operates through an efficient tandem dynamic kinetic asymmetric reductive amination (ara)/lactamization, and produces chiral fused tricyclic lactams in high yields and excellent diastereo- and enantioselectivities (up to >99% ee, >20:1 dr and 98% yield). |
2023-04-22 |
2023-08-14 |
Not clear |
| Hao Jiang, Xiang-Kui He, Xuan Jiang, Wei Zhao, Liang-Qiu Lu, Ying Cheng, Wen-Jing Xia. Photoinduced Cobalt-Catalyzed Desymmetrization of Dialdehydes to Access Axial Chirality. Journal of the American Chemical Society. 2023-03-15. PMID:36920031. |
herein, we report two visible light-induced cobalt-catalyzed asymmetric reductive couplings of biaryl dialdehydes to synthesize axially chiral aldehydes (60 examples, up to 98% yield, >19:1 dr, and >99% ee). |
2023-03-15 |
2023-08-14 |
Not clear |
| Pengwei Ji, Xiaopei Liu, Jiwei Xu, Xu Zhang, Jianhua Guo, Wen-Wen Chen, Baoguo Zha. Direct Asymmetric α-C-H Addition of N-unprotected Propargylic Amines to Trifluoromethyl Ketones by Carbonyl Catalysis. Angewandte Chemie (International ed. in English). 2022-10-09. PMID:36210342. |
by using a chiral pyridoxal as carbonyl catalyst, we have successfully realized direct asymmetric a-c-h addition of n-unprotected propargylic amines to trifluoromethyl ketones, producing a broad range of chiral alkynyl b-aminoalcohols in 54~84% yields with excellent stereoselectivities (up to 20:1 dr and 99% ee). |
2022-10-09 |
2023-08-14 |
Not clear |
| Jesse J Jung, Shen Yi Lim, Xavier Chan, Srinivas R Sadda, Quan V Hoan. Correlation of Diabetic Disease Severity to Degree of Quadrant Asymmetry in En Face OCTA Metrics. Investigative ophthalmology & visual science. vol 63. issue 9. 2022-08-09. PMID:35943732. |
to determine if diabetic retinopathy (dr) severity affects quadrant asymmetry (qa) of optical coherence tomography angiography (octa) metrics differentially. |
2022-08-09 |
2023-08-14 |
Not clear |
| Wei Wang, Fangqing Zhang, Yangbin Liu, Xiaoming Fen. Diastereo- and Enantioselective Construction of Vicinal All-Carbon Quaternary Stereocenters via Iridium/Europium Bimetallic Catalysis. Angewandte Chemie (International ed. in English). 2022-08-02. PMID:35916194. |
we here report a synergistic bimetallic catalysis via a chiral n,n' -dioxide-europium (eu) complex and a phosphoramidite-iridium (ir) catalyst for the asymmetric allylation of oxindole derivatives by using challenging trisubstituted allylic esters. the allylated products bearing vicinal all-carbon quaternary stereocenters were obtained with good diastereoselectivities (up to 20:1 dr) and excellent enantioselectivities (up to 99% ee). |
2022-08-02 |
2023-08-14 |
Not clear |
| Jing Qian, Zeeshan Haq, Daphne Yang, Jay M Stewar. Male sex increases the risk of diabetic retinopathy in an urban safety-net hospital population without impacting the relationship between axial length and retinopathy. Scientific reports. vol 12. issue 1. 2022-06-13. PMID:35697817. |
in the subset of patients with asymmetric dr, the percentage of patients whose shorter eye had a higher stage of dr was not significantly different between men and women (p = 0.20). |
2022-06-13 |
2023-08-14 |
Not clear |
| Jacqkis Davis, Mojgan Gharaee, Chamini V Karunaratne, Jose Cortes Vazquez, Mikayla Haynes, Weiwei Luo, Vladimir N Nesterov, Thomas Cundari, Hong Wan. Asymmetric Synthesis of Chromans through Bifunctional Enamine-Metal Lewis Acid Catalysis. Chemistry (Weinheim an der Bergstrasse, Germany). 2022-03-17. PMID:35298095. |
a concise synthetic method for asymmetric synthesis of chromans from cyclohexanones and salicylaldehydes has been developed to afford tricyclic chromans containing three consecutive stereogenic centers in good yields (up to 87%) and stereoselectivity (up to 99% ee and 11:1:1 dr). |
2022-03-17 |
2023-08-13 |
Not clear |
| Wendian Li, Tilong Yang, Nan Song, Ruihao Li, Jiao Long, Lin He, Xumu Zhang, Hui L. Ir/f-Ampha complex catalyzed asymmetric sequential hydrogenation of enones: a general access to chiral alcohols with two contiguous chiral centers. Chemical science. vol 13. issue 6. 2022-03-14. PMID:35282638. |
a general and highly efficient method for asymmetric sequential hydrogenation of α,β-unsaturated ketones has been developed by using an iridium/f-ampha complex as the catalyst, furnishing corresponding chiral alcohols with two contiguous stereocenters in high yields with excellent diastereo- and enantioselectivities (up to 99% yield, >20 : 1 dr and >99% ee). |
2022-03-14 |
2023-08-13 |
Not clear |
| Nessan Joseph Kerrigan, Mukulesh Mondal, Shubhanjan Mitra, Dylan J Twardy, Manashi Panda, Kraig A Wheele. Asymmetric Synthesis of Bicyclic Pyrazolidinones through Alkaloid-Catalyzed [3 + 2]-Cycloadditions of Ketenes and Azomethine Imines. Chemistry (Weinheim an der Bergstrasse, Germany). 2022-02-17. PMID:35175649. |
a versatile asymmetric synthesis of bicyclic pyrazolidinones through alkaloid-catalyzed formal [3 + 2]- and [3 + 2 + 2]-cycloadditions of ketenes with azomethine imines is described. the methodology was found to be tolerant of ketene and a variety of monosubstituted ketenes (r = alkyl, oac). the products were formed in good to excellent yields (71-99% for 24 examples, 39 examples in all), with good to excellent diastereoselectivity in many cases (dr 3:1 to 27:1 for 22 examples), and with excellent enantioselectivity for most examples (≥93% ee for 34 products). in the case of most disubstituted ketenes, the reaction proceeded through a [3 + 2 + 2]-cycloaddition to form structurally interesting bicyclic pyrazolo-oxadiazepinediones with moderate diastereoselectivity (dr up to 3.7:1) and as racemic mixtures (3 examples). the method represents the first unambiguous example of an enantioselective reaction between ketenes and a 1,3-dipole. |
2022-02-17 |
2023-08-13 |
Not clear |
| Yu-Han Nie, Masaaki Komatsuda, Ping Yang, Chao Zheng, Junichiro Yamaguchi, Shu-Li Yo. Pd-Catalyzed Asymmetric Dearomative Arylation of Indoles via a Desymmetrization Strategy. Organic letters. 2022-02-14. PMID:35156828. |
this method provides a convenient synthesis of spiroindolenines bearing two stereogenic centers in good yields (up to 98%) with excellent diastereo- and enantioselectivities (up to >20:1 dr and 97% ee), which could also be applied in asymmetric dearomative arylation of the simple c3-tethered indoles. |
2022-02-14 |
2023-08-13 |
Not clear |
| Toshimichi Kobayashi, Soshi Nishino, Masahiro Miura, Koji Hiran. Synthesis of β-Silyl-α-amino Acid Derivatives by Cu-Catalyzed Regio- and Enantioselective Silylamination of α,β-Unsaturated Esters. Organic letters. 2022-02-03. PMID:35112875. |
additionally, by using a suitable chiral bisphosphine ligand, the asymmetric induction is possible, delivering the optically active β-silyl-α-amino acids with synthetically acceptable diastereomeric ratios (55:45-82:18 dr) and high enantiomeric ratios (81:19-99:1 er). |
2022-02-03 |
2023-08-13 |
Not clear |
| Yongqiang Tu, Ju-Song Yang, Ka Lu, Chen-Xiao Li, Zu-Hang Zhao, Xiao-Ming Zhang, Fu-Min Zhan. Chiral 1,2,3-Triazolium Salt Catalyzed Asymmetric Mono- and Dialkylation of 2,5-Diketopiperazines with the Construction of Tetrasubstituted Carbon Centers. Angewandte Chemie (International ed. in English). 2022-01-04. PMID:34981881. |
the reactions feature high yields (up to 98 %), and excellent cis-diastereo- and enantioselectivities (up to >20:1 dr, >99% ee), and they provide a new asymmetric synthetic approach to important functionalized 2,5-diketopiperazine skeletons. |
2022-01-04 |
2023-08-13 |
Not clear |
| Rajvardhan Azad, Sony Sinha, Prateek Nishan. Asymmetric diabetic retinopathy. Indian journal of ophthalmology. vol 69. issue 11. 2021-11-04. PMID:34708738. |
increasing prevalence of diabetes mellitus warrants recognition of factors related to asymmetric diabetic retinopathy (dr). |
2021-11-04 |
2023-08-13 |
Not clear |
| Rajvardhan Azad, Sony Sinha, Prateek Nishan. Asymmetric diabetic retinopathy. Indian journal of ophthalmology. vol 69. issue 11. 2021-11-04. PMID:34708738. |
asymmetric dr is defined as proliferative dr (pdr) in one eye and nonproliferative, preproliferative, background, or no dr in the other eye lasting for at least 2 years. |
2021-11-04 |
2023-08-13 |
Not clear |
| Rajvardhan Azad, Sony Sinha, Prateek Nishan. Asymmetric diabetic retinopathy. Indian journal of ophthalmology. vol 69. issue 11. 2021-11-04. PMID:34708738. |
the gamut of diagnostic modalities for asymmetric dr includes thorough ocular examination, slit-lamp biomicroscopy, fundus photography, fundus fluorescein angiography, optical coherence tomography, and newer modalities such as ultra-widefield fluorescein angiography and optical coherence tomography angiography, along with a complete systemic evaluation and carotid doppler studies. |
2021-11-04 |
2023-08-13 |
Not clear |
| Rajvardhan Azad, Sony Sinha, Prateek Nishan. Asymmetric diabetic retinopathy. Indian journal of ophthalmology. vol 69. issue 11. 2021-11-04. PMID:34708738. |
this review discusses in detail the aforementioned considerations and draws a comprehensive picture of asymmetric dr in order to sensitize ophthalmologists to this important condition. |
2021-11-04 |
2023-08-13 |
Not clear |
| Ke-Wei Chen, Dan-Dan Wang, Si-Jia Liu, Xue Wang, Yu-Chen Zhang, Yi-Ming Tian, Qiong Wu, Feng Sh. Application of 3-Alkyl-2-vinylindoles in Catalytic Asymmetric Dearomative (2+3) Cycloadditions. The Journal of organic chemistry. vol 86. issue 15. 2021-10-05. PMID:34313431. |
the first application of 3-alkyl-2-vinylindoles in catalytic asymmetric dearomative cycloadditions was established by chiral phosphoric acid (cpa)-catalyzed (2+3) cycloaddition with azoalkenes, leading to the generation of chiral pyrroloindolines bearing two tetrasubstituted stereogenic centers in good yields (61-96%) and excellent stereoselectivities (all >95:5 dr, 86-99% ee). |
2021-10-05 |
2023-08-13 |
Not clear |
| Juzhang Yan, Xiurong Zheng, Yangqing Zheng, Ruoting Zhan, Huicai Huan. Asymmetric Michael reaction of 3-homoacyl coumarins with chromone-fused dienes toward enantioenriched coumarin chromone skeletons. Organic & biomolecular chemistry. vol 19. issue 37. 2021-09-29. PMID:34494052. |
asymmetric michael reaction of 3-homoacyl coumarins and chromone-fused dienes was developed by employing a chiral squaramide, and a series of coumarin chromone skeletons were furnished in moderate to high yields (up to 99%) and stereoselectivities (up to 98 : 2 dr, 99% ee). |
2021-09-29 |
2023-08-13 |
Not clear |