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Ma J, Ye Q, Green RA, Gurak J, Ayers S, Huang Y, Miller SA. Overcoming NMR line broadening of nitrogen containing compounds: A simple solution. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2024; 62:198-207. [PMID: 38258438 DOI: 10.1002/mrc.5432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024]
Abstract
This study presents a straightforward solution to the challenge of elucidating the structures of nitrogen containing compounds undergoing isomerization. When spectral line broadening occurs related to isomerization, be it prototropic tautomerism or bond rotations, this poses a significant obstacle to structural elucidation. By adding acids, we demonstrate a simple approach to overcome this issue and effectively sharpen NMR signals for acid stable prototropic tautomers as well as the conformational isomers containing a morpholine or piperazine ring.
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Affiliation(s)
- Junhe Ma
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey, USA
| | - Qingmei Ye
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey, USA
| | - Rebecca A Green
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey, USA
| | - John Gurak
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey, USA
| | - Sloan Ayers
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey, USA
| | - Yande Huang
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey, USA
| | - Scott A Miller
- Chemical Process Development, Bristol Myers Squibb Company, New Brunswick, New Jersey, USA
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2
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Evenson GE, Powell WC, Hinds AB, Walczak MA. Catalytic Amide Activation with Thermally Stable Molybdenum(VI) Dioxide Complexes. J Org Chem 2023; 88:6192-6202. [PMID: 37027833 PMCID: PMC10422866 DOI: 10.1021/acs.joc.3c00218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
Oxazolines and thiazolines are important constituents of bioactive natural products and pharmaceuticals. Here, we report the development of an effective and practical method of oxazoline and thiazoline formation, which can facilitate the synthesis of natural products, chiral ligands, and pharmaceutical intermediates. This method capitalized on a Mo(VI) dioxide catalyst stabilized by substituted picolinic acid ligands, which is tolerant to many functional groups that would otherwise be sensitive to highly electrophilic alternative reagents.
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Affiliation(s)
- Garrett E Evenson
- University of Colorado, Department of Chemistry, Boulder, Colorado 80309, United States
| | - Wyatt C Powell
- University of Colorado, Department of Chemistry, Boulder, Colorado 80309, United States
| | - Aaron B Hinds
- University of Colorado, Department of Chemistry, Boulder, Colorado 80309, United States
| | - Maciej A Walczak
- University of Colorado, Department of Chemistry, Boulder, Colorado 80309, United States
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Mushtaq A, Zahoor AF, Bilal M, Hussain SM, Irfan M, Akhtar R, Irfan A, Kotwica-Mojzych K, Mojzych M. Sharpless Asymmetric Dihydroxylation: An Impressive Gadget for the Synthesis of Natural Products: A Review. Molecules 2023; 28:2722. [PMID: 36985698 PMCID: PMC10051988 DOI: 10.3390/molecules28062722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/21/2023] [Accepted: 03/07/2023] [Indexed: 03/30/2023] Open
Abstract
Sharpless asymmetric dihydroxylation is an important reaction in the enantioselective synthesis of chiral vicinal diols that involves the treatment of alkene with osmium tetroxide along with optically active quinine ligand. Sharpless introduced this methodology after considering the importance of enantioselectivity in the total synthesis of medicinally important compounds. Vicinal diols, produced as a result of this reaction, act as intermediates in the synthesis of different naturally occurring compounds. Hence, Sharpless asymmetric dihydroxylation plays an important role in synthetic organic chemistry due to its undeniable contribution to the synthesis of biologically active organic compounds. This review emphasizes the significance of Sharpless asymmetric dihydroxylation in the total synthesis of various natural products, published since 2020.
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Affiliation(s)
- Aqsa Mushtaq
- Medicinal Chemistry Research Lab, Department of Chemistry, Government College University Faisalabad, Faisalabad 38000, Pakistan
| | - Ameer Fawad Zahoor
- Medicinal Chemistry Research Lab, Department of Chemistry, Government College University Faisalabad, Faisalabad 38000, Pakistan
| | - Muhammad Bilal
- College of Computer Science and Technology, Zhejiang University, Hangzhou 310027, China
| | - Syed Makhdoom Hussain
- Department of Zoology, Government College University Faisalabad, Faisalabad 38000, Pakistan
| | - Muhammad Irfan
- Department of Pharmaceutics, Government College University Faisalabad, Faisalabad 38000, Pakistan
| | - Rabia Akhtar
- Medicinal Chemistry Research Lab, Department of Chemistry, Government College University Faisalabad, Faisalabad 38000, Pakistan
- Department of Chemistry, Superior University, Faisalabad 38000, Pakistan
| | - Ali Irfan
- Medicinal Chemistry Research Lab, Department of Chemistry, Government College University Faisalabad, Faisalabad 38000, Pakistan
| | - Katarzyna Kotwica-Mojzych
- Laboratory of Experimental Cytology, Medical University of Lublin, Radziwiłłowska 11, 20-080 Lublin, Poland
| | - Mariusz Mojzych
- Department of Chemistry, Siedlce University of Natural Sciences and Humanities, 3-Go Maja 54, 08-110 Siedlce, Poland
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Srivastava N, Ha H. Highly Efficient and Stereoselective Mukaiyama Aldol Reaction with Chiral Aziridine‐2‐carboxaldehyde and Its Synthetic Applications. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202100567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nikhil Srivastava
- Department of Chemistry Hankuk University of Foreign Studies 17035 Yongin (Republic of Korea
| | - Hyun‐Joon Ha
- Department of Chemistry Hankuk University of Foreign Studies 17035 Yongin (Republic of Korea
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