Related Experiment Video
Updated: May 22, 2025

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
Copper-Catalyzed Formal Aldehydic C-H Borylation Enabled by an sp2-sp3 Diboron Reagent
Jiaxin Lin1, Peiqi Zhang1, Xiangyu Lou2
1Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
Abstract:
We have developed a copper-catalyzed formal aldehydic C-H borylation using a neutral sp2-sp3 diboron reagent, LBH2-Bpin (where L is a σ-donor), leading to the one-pot synthesis of diverse acylboranes. Notably, the BH moieties in the acylborane can be further used to construct boracycles. This protocol enables straightforward functional group (FG) replacement of commercial medicines with an acylboron motif. Detailed mechanistic studies and DFT calculations reveal a synergistic hydride transfer pathway, which is promoted by the electron-rich nature of the LBH2 fragment. This investigation highlights the potential of the new diboron reagent in accessing reaction modes that were previously unachievable.
Related Concept Videos
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Hydroboration-Oxidation of Alkenes
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an ÃÂñ-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the âÃÂÃÂOH group.
Base-Promoted α-Halogenation of Aldehydes and Ketones
α-Alkylation of Ketones via Enolate Ions

![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)