Publications by authors named "Weihui Zhong"

15 Publications

  • Page 1 of 1

Enantioselective synthesis of functionalized 1,4-dihydropyrazolo-[4',3':5,6]pyrano[2,3-]quinolines through ferrocenyl-phosphine-catalyzed annulation of modified MBH carbonates and pyrazolones.

Chem Commun (Camb) 2021 May;57(38):4690-4693

College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.

An enantioselective synthesis of highly functionalized 1,4-dihydropyrazolo[4',3':5,6]pyrano[2,3-b]quinolines from modified MBH carbonates and pyrazolones via a chiral phosphine-mediated alkylation/annulation sequence has been realized. The chiral dihydropyrano[2,3-c]pyrazoles bearing bio-active condensed heterocycles were facilely formed in good chemical yields and with high to excellent enantioselectivity by utilizing low catalyst loading.
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http://dx.doi.org/10.1039/d1cc00989cDOI Listing
May 2021

Correction: Enantioselective synthesis of functionalized 1,4-dihydropyrazolo-[4',3':5,6]pyrano[2,3-b]quinolines through ferrocenyl-phosphine-catalyzed annulation of modified MBH carbonates and pyrazolones.

Chem Commun (Camb) 2021 May 21;57(35):4331. Epub 2021 Apr 21.

Institute of Pharmaceutical Science and Technology, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.

Correction for 'Enantioselective synthesis of functionalized 1,4-dihydropyrazolo-[4',3':5,6]pyrano[2,3-b]quinolines through ferrocenyl-phosphine-catalyzed annulation of modified MBH carbonates and pyrazolones' by Xiao Xiao et al., Chem. Commun., 2021, DOI: .
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http://dx.doi.org/10.1039/d1cc90146jDOI Listing
May 2021

Ruthenium-Catalyzed Electrochemical Synthesis of Indolines through Dehydrogenative [3 + 2] Annulation with H Evolution.

J Org Chem 2020 Nov 13;85(21):13735-13746. Epub 2020 Oct 13.

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.

A dehydrogenative [3 + 2] annulation reaction of aniline derivatives and alkenes has been developed via the ruthenium-electron catalytic systems for the synthesis of versatile indolines. Electricity is used as a sustainable oxidant to regenerate the active Ru(II) catalyst and promote H evolution. This protocol is ecofriendly and easy to handle as it uses a simple undivided cell in mild conditions without the employment of metal oxidants.
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http://dx.doi.org/10.1021/acs.joc.0c01879DOI Listing
November 2020

Syntheses of -Alkyl 2-Arylindoles from Saturated Ketones and 2-Arylethynylanilines via Cu-Catalyzed Sequential Dehydrogenation/Aza-Michael Addition/Annulation Cascade.

J Org Chem 2020 03 14;85(5):3224-3233. Epub 2020 Feb 14.

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China.

We describe here a Cu-catalyzed and 4-OH-TEMPO-mediated sequential dehydrogenation/aza-Michael addition/annulation cascade reaction for the construction of -alkyl 2-arylindoles from facilely available saturated ketones and 2-arylethynylanilines. This reaction shows high regioselectivity and tolerates a variety of functional groups. Moreover, 3-alkyl-substituted indoles can also be achieved when using 2-alkylethynylanilines as starting materials.
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http://dx.doi.org/10.1021/acs.joc.9b03091DOI Listing
March 2020

Highly Enantioselective Hydrogenation of Non--Substituted 2-Pyridyl Aryl Ketones via Iridium--Diaphos Catalysis.

Org Lett 2019 Jul 26;21(14):5392-5396. Epub 2019 Jun 26.

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences , Zhejiang University of Technology , Hangzhou 310014 , People's Republic of China.

This work disclosed a highly enantioselective hydrogenation of non--substituted 2-pyridyl aryl ketones via Ir/-diaphos catalysis. This catalytic system allows for full control over the configuration of the stereocenter, affording two enantiomers of the desired products with extremely high enantioselectivity (up to >99% ee in most cases) and excellent reactivity (TON of up to 19600, TOF of 1633 h) under mild conditions. Density functional theory calculations and control experiments revealed that the relay hydrogen bonding among the solvent isopropanol, substrate, and ligand is crucial for high ee's.
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http://dx.doi.org/10.1021/acs.orglett.9b01415DOI Listing
July 2019

Highly Enantioselective Synthesis of Chiral Benzhydrols via Manganese Catalyzed Asymmetric Hydrogenation of Unsymmetrical Benzophenones Using an Imidazole-Based Chiral PNN Tridentate Ligand.

Org Lett 2019 06 29;21(11):3937-3941. Epub 2019 May 29.

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences , Zhejiang University of Technology , Hangzhou 310014 , People's Republic of China.

A series of Mn(I) catalysts containing imidazole-based chiral PNN tridentate ligands with controllable "side arm" groups have been established, enabling the asymmetrical hydrogenation of unsymmetrical benzophenones with outstanding activity (up to 13 000 TON) and excellent enantioselectivity (up to >99% ee). This protocol uses KCO as an industrially desirable base and features a wide substrate scope and functional group tolerance. Moreover, the imine group in the catalyst is crucial for accessing high activities and good enantioselectivities.
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http://dx.doi.org/10.1021/acs.orglett.9b01056DOI Listing
June 2019

B(CF)-catalyzed Markovnikov addition of indoles to aryl alkynes: an approach toward bis(indolyl)alkanes.

Org Biomol Chem 2018 12;16(47):9274-9278

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.

The first example of the metal- and solvent-free B(C6F5)3-catalyzed Markovnikov addition of indoles to aryl alkynes was disclosed. Both N-H and N-protected indoles were tolerated, leading to a wide spectrum of versatile bis(indolyl)alkanes in moderate to good yields with high regioselectivities.
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http://dx.doi.org/10.1039/c8ob02805bDOI Listing
December 2018

B(CF)-Catalyzed Asymmetric Reductive Amination of Ketones with Ammonia Borane.

J Org Chem 2018 Oct 12;83(19):11502-11509. Epub 2018 Sep 12.

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences , Zhejiang University of Technology , Hangzhou 310014 , People's Republic of China.

The first example of metal-free B(CF)-catalyzed asymmetric reduction amination of ketones with chiral α-methylbenzylamine (α-MBA) using ammonia borane as the reductant is reported. This one-pot method has a broad substrate scope and provides various chiral amines in 81-95% yield with 80-99% de. This protocol was further applied in the total synthesis of cinacalcet.
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http://dx.doi.org/10.1021/acs.joc.8b01362DOI Listing
October 2018

Development of Ferrocene-Based Diamine-Phosphine-Sulfonamide Ligands for Iridium-Catalyzed Asymmetric Hydrogenation of Ketones.

J Org Chem 2018 09 13;83(18):10749-10761. Epub 2018 Aug 13.

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences , Zhejiang University of Technology , Hangzhou 310014 , People's Republic of China.

A series of air-stable, easily accessible tridentate ferrocene-based diamine-phosphine sulfonamide (f-diaphos) ligands were successfully developed for iridium-catalyzed asymmetric hydrogenation of ketones. The f-diaphos ligands exhibited excellent enantioselectivity and superb reactivity in Ir-catalyzed asymmetric hydrogenation of ketones (for arylalkyl ketones, ( S)-selectivity, up to 99.4% ee, and 100 000 TON; for diaryl ketones, ( R)-selectivity, up to 98.2% ee, and 10 000 TON). This protocol could be easily conducted on gram scale, thereby providing a chance to various drugs.
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http://dx.doi.org/10.1021/acs.joc.8b01276DOI Listing
September 2018

Metal-Oxidant-Free Cobalt-Catalyzed C(sp)-H Carbonylation of ortho-Arylanilines: An Approach toward Free ( NH)-Phenanthridinones.

J Org Chem 2018 05 10;83(10):5698-5706. Epub 2018 May 10.

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences , Zhejiang University of Technology , Hangzhou 310014 , People's Republic of China.

A traceless directing group assisted Co-catalyzed C(sp)-H carbonylation of ortho-arylanilines for the synthesis of free ( NH)-phenanthridinones in metal-based-oxidant-free fashion was accomplished. This protocol employs diisopropyl azodicarboxylate as the CO source and oxygen as the sole oxidant, and provides good yields with various functional tolerance. The methodology has been applied for the total synthesis of PARP inhibitor PJ-34. Furthermore, the kinetic isotopic effect experiments reveal the C-H bond cleavage probably occurred in the rate-determining step.
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http://dx.doi.org/10.1021/acs.joc.8b00730DOI Listing
May 2018

The cinchona alkaloid squaramide catalyzed asymmetric Pictet-Spengler reaction and related theoretical studies.

Org Biomol Chem 2018 01;16(4):566-574

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, P R China.

The asymmetric Pictet-Spengler reaction between tryptamine derivatives and aldehydes has been developed with a cinchona alkaloid squaramide as the catalyst, affording the corresponding tetrahedron-β-carbolines in good to excellent yields and ee values. A rational mechanistic pathway has also been proposed based on DFT calculations.
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http://dx.doi.org/10.1039/c7ob02606dDOI Listing
January 2018

Phosphine-catalyzed [3 + 2] annulation reaction: highly regio- and diastereoselective synthesis of 2-azaspiro[4.4]nonene-1,3-diones.

Org Biomol Chem 2017 Sep;15(36):7523-7526

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, P R China.

A novel phosphine-catalyzed [3 + 2] annulation of γ-substituted allenoates with succinimides was developed, which was successfully applied to the synthesis of 2-azaspiro[4.4]nonene-1,3-dione derivatives. The reaction afforded the desired products in moderate to high yields (up to 96%) with excellent regioselectivities and diastereoselectivities (up to >99 : 1 dr). A plausible reaction mechanism has also been proposed based on previous literature.
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http://dx.doi.org/10.1039/c7ob01957bDOI Listing
September 2017

Separation and characterization of unknown impurities in cefonicid sodium by trap-free two-dimensional liquid chromatography combined with ion trap time-of-flight mass spectrometry.

Rapid Commun Mass Spectrom 2017 Sep;31(18):1541-1550

Zhejiang University of Technology, Hangzhou, 310014, China.

Rationale: Seven unknown antibiotic impurities in cefonicid sodium were separated and characterized by a trap-free two-dimensional liquid chromatography coupled to high-resolution ion-trap time-of-flight mass spectrometry (2D-LC/IT-TOF MS) using both positive and negative modes of electrospray ionization. Trap-free 2D-LC and an online demineralization technique made it possible to characterize cefonicid sodium under the conditions of the official standard, and the TIC chromatogram obtained by LC/MS was in conformity with the LC chromatogram obtained by the official analytical method in the peak sequence of impurities.

Methods: In the first dimension, the column was a GRACE Alltima C (250 mm × 4.6 mm, 5 μm), and the gradient elution used 0.02 mol·L ammonium dihydrogen phosphate solution and methanol as mobile phase. In the second dimension, the analytical column was a Shimadzu Shim-pack GISS C (50 mm × 2.1 mm, 1.9 μm) with 10 mmol·L ammonium formate solution and methanol as mobile phase. Full scan LC/MS was first executed to obtain the exact m/z values of the molecules. Then LC/MS and LC-MS experiments were performed on the compounds of interest.

Results: The structures of seven unknown degradation products in cefonicid sodium were deduced based on the high-resolution MS data using both positive and negative mode.

Conclusions: The problem of incompatibility between the non-volatile salt mobile phase and mass spectrometry was solved completely by multidimensional heart-cutting approaches and an online demineralization technique, which is worthy of widespread use and application for the advantages of stability and repeatability.
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http://dx.doi.org/10.1002/rcm.7934DOI Listing
September 2017

Study of the structures of photodegradation impurities and pathways of photodegradation of cilnidipine by liquid chromatography/Q-Orbitrap mass spectrometry.

Rapid Commun Mass Spectrom 2016 08;30(15):1771-8

Zhejiang Institute for Food and Drug Control, Hangzhou, 310053, China.

Rationale: The structures of photodegradation impurities in cilnidipine were studied by liquid chromatography/Q-Orbitrap mass spectrometry (LC/Q-Orbitrap MS) for the further improvement of the official monographs in Pharmacopoeias. The complete fragmentation patterns of impurities were investigated to obtain their structural information. Two pathways of photodegradation of cilnidipine were also explored to clarify the source of impurities in cilnidipine.

Methods: Chromatographic separation was performed on a Boston Group C18 column (250 mm × 4.6 mm, 5 μm). The mobile phase consisted of acetonitrile/H2 O at a ratio of 75:25 (v/v). In order to determine the m/z values of the molecular ions and formulas of all detected impurities, full scan LC/MS in both positive and negative ion modes was firstly performed using a Thermo LC system coupled with a Q-Orbitrap high-resolution mass spectrometer. LC/MS/MS analysis was also carried out on target compounds to obtain as much structural information as possible.

Results: Five novel photodegradation impurities of cilnidipine were separated and identified based on the high-resolution MS/MS data. Impurity III was synthesized and its structure was confirmed by (1) H-NMR and (13) C-NMR data. Two photodegradation pathways to produce different photodegradation impurities were also revealed in this study.

Conclusions: Among those impurities, impurities II and III were the main impurities which existed in the cilnidipine available on the market. Impurity II (the Z-isomer) was mainly produced when cilnidipine powder was directly exposed to daylight while impurity III (containing a piperidine ring) was mainly produced when cilnidipine was exposed to daylight in an ethanolic solution. Copyright © 2016 John Wiley & Sons, Ltd.
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http://dx.doi.org/10.1002/rcm.7657DOI Listing
August 2016

Chiral bifunctional ferrocenylphosphine catalyzed highly enantioselective [3 + 2] cycloaddition reaction.

Org Biomol Chem 2016 Jan;14(2):752-760

Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, PR China.

A series of air-stable ferrocenylphosphines LB1-LB8 were designed and prepared in high yields. (R,SFc)-ferrocenylphosphine LB5 was found to efficiently promote the asymmetric [3 + 2] cycloaddition of Morita-Baylis-Hillman carbonates with maleimides to afford the corresponding bicyclic imides with 84-99% ee and 67-99% yield. Interestingly, the configuration of these products was contrary to those reported in the literature.
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http://dx.doi.org/10.1039/c5ob01958cDOI Listing
January 2016
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