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Borane catalyzed selective diazo cross-coupling towards pyrazoles

Citation

Dasgupta, A and Pahar, S and Babaahmadi, R and Gierlichs, L and Yates, BF and Ariafard, A and Melen, RL, Borane catalyzed selective diazo cross-coupling towards pyrazoles, Advanced Synthesis and Catalysis, 364, (4) pp. 773-780. ISSN 1615-4150 (2022) [Refereed Article]


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DOI: doi:10.1002/adsc.202101312

Abstract

Decomposition of donor-acceptor diazo compounds leads to the formation of reactive carbene intermediates. These can undergo a wide variety of carbene transfer reactions to yield synthetically useful products. Herein, we report a selective borane catalyzed cyclization reaction from the combination of two different diazo compounds to afford N-substituted pyrazoles. The selective decomposition of the more reactive α-aryl α-diazoester and subsequent reaction with a vinyl diazoacetate produces N-alkylated pyrazoles in a regioselective manner. Catalytic amounts of tris(pentafluorophenyl)borane (10 mol%) were employed to afford the pyrazole products (36 examples) in yields from 59 to 80%. Extensive DFT studies have been undertaken to interpret the mechanism for this reaction which was found to go through two tandem catalytic cycles, both catalyzed by B(C6F5)3.

Item Details

Item Type:Refereed Article
Keywords:borane catalysis, DFT calculations, diazo compounds, diazoester, pyrazole, carbene, tris(pentafluorophenyl)borane, Density Functional Theory
Research Division:Chemical Sciences
Research Group:Physical chemistry
Research Field:Catalysis and mechanisms of reactions
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the chemical sciences
UTAS Author:Babaahmadi, R (Mr Rasool Babaahmadi)
UTAS Author:Yates, BF (Professor Brian Yates)
UTAS Author:Ariafard, A (Associate Professor Alireza Ariafard)
ID Code:150055
Year Published:2022
Funding Support:Australian Research Council (DP180100904)
Web of Science® Times Cited:4
Deposited By:College Office - CoSE
Deposited On:2022-05-16
Last Modified:2022-05-18
Downloads:0

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