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Updated: Oct 27, 2025
A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Direct, Catalytic α-Alkylation of N-Heterocycles by Hydroaminoalkylation: Substrate Effects for Regiodivergent
Rebecca C DiPucchio1, Karst E Lenzen1, Pargol Daneshmand1
1Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1.
Abstract:
Saturated N-heterocycles are prevalent in pharmaceutical and agrochemical industries, yet remain challenging to catalytically alkylate. Most strategies for C-H activation of these challenging substrates use protected amines or high loadings of precious metal catalysts. We report an early transition-metal system for the broad, robust, and direct alkylation of unprotected amine heterocycles with simple alkenes. Short reaction times are achieved using an in situ generated tantalum catalyst that avoids the use of bases, excess substrate, or additives. In most cases, this catalyst system is selective for the branched reaction product, including examples of products that are generated with excellent diastereoselectivity. Alkene electronic properties can be exploited for substrate-modified regioselectivity to access the alternative linear amine alkylation product with a group 5 catalyst. This method allows for the facile isolation of unprotected N-heterocyclic products, as useful substrates for further reactivity.
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