Publications by authors named "Rajani Thapa Magar"

3 Publications

  • Page 1 of 1

A Future Perspective on Phototriggered Isomerizations of Transition Metal Sulfoxides and Related Complexes.

J Am Chem Soc 2021 01 5;143(2):526-537. Epub 2021 Jan 5.

Department of Chemistry and Chemical Biology, 300 Terrace Street NE, University of New Mexico, Albuquerque, New Mexico 87131-001 United States.

Photochromic molecules are examples of light-activated bistable molecules. We highlight the design criteria for a class of ruthenium and osmium sulfoxide complexes that undergo phototriggered isomerization of the bound sulfoxide. The mode of action in these complexes is an excited-state isomerization of the sulfoxide from S-bonded to O-bonded. We discuss the basic mechanism for this transformation and highlight specific examples that demonstrate the effectiveness and efficiency of the isomerization. We subsequently discuss future research directions within the field of phototriggered sulfoxide isomerizations on transition metal polypyridine complexes. These efforts involve new synthetic directions, including the choice of metal as well as new ambidentate ligands for isomerization.
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http://dx.doi.org/10.1021/jacs.0c08820DOI Listing
January 2021

Ni-catalysed regioselective 1,2-diarylation of unactivated olefins by stabilizing Heck intermediates as pyridylsilyl-coordinated transient metallacycles.

Chem Sci 2018 Jan 27;9(4):904-909. Epub 2017 Nov 27.

Department of Chemistry & Chemical Biology , The University of New Mexico , Albuquerque , NM 87131 , USA . Email:

We report a Ni-catalysed diarylation of unactivated olefins in dimethylpyridylvinylsilane by intercepting Heck C(sp)-NiX intermediates, derived from aryl halides, with arylzinc reagents. This approach utilizes a modifiable pyridylsilyl moiety as a coordinating group that plays a dual role of intercepting oxidative addition species to promote Heck carbometallation, and stabilizing the Heck C(sp)-NiX intermediates as transient metallacycles to suppress β-hydride elimination, and facilitate transmetalation/reductive elimination. This method affords 1,2-diarylethylsilanes, which can be readily oxidized to 1,2-diarylethanols that occur as structural motifs in 3-aryl-3,4-dihydroisocoumarin and dihydrostilbenoid natural products.
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http://dx.doi.org/10.1039/c7sc04351aDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872806PMC
January 2018

Pd-Catalyzed Regioselective 1,2-Dicarbofunctionalization of Unactivated Olefins by a Heck Reaction/Enolate Cyclization Cascade.

Org Lett 2017 04 6;19(8):2154-2157. Epub 2017 Apr 6.

Department of Chemistry & Chemical Biology, The University of New Mexico , Albuquerque, New Mexico 87131, United States.

We disclose a Pd-catalyzed reaction protocol that regioselectively difunctionalizes unactivated olefins with aryl iodides and tethered enolates. The current method allows the rapid synthesis of a variety of 1,3,4-trisubstituted pyrrolidinones from simple and readily available amides. We further demonstrate this new method's application by postsynthetically modifying the arylacetic acid side chains of two commercial nonsteroidal anti-inflammatory drugs, indomethacin and tolmetin, to highly decorated 4-benzylpyrrolidinone frameworks. Mechanistic studies reveal that the reaction proceeds via a Heck reaction/enolate cyclization cascade, a process that exploits β-H elimination in a constructive mode for regioselective 1,2-difunctionalization of unactivated olefins.
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http://dx.doi.org/10.1021/acs.orglett.7b00794DOI Listing
April 2017