Related Experiment Video
Updated: Jun 9, 2026

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
Triarylborane-Promoted Cyano-Mukaiyama Aldol Reaction Involving a 1,5-Metalate Shift
Hongliang Zhao1, Meijun Xiong2, Qing Han3
1High & New Technology Research Center, Henan Academy of Sciences, Zhengzhou 450002, P. R. China.
Abstract:
A cascade reaction of in situ generated cyano-allenol ethers with triphenylboranes has been developed, which provides an efficient protocol for the synthesis of functionalized 3-aminoindenonones under mild conditions. This method features a broad substrate scope and an excellent functional group tolerance. Notably, BAr3 plays a dual role in the transformation: it functions as a Lewis acid to activate the cyano group, initiating the Mukaiyama aldol addition, and also serves as a coordination bridge that links the iminium intermediate with the aryl donor through the formation of an "ate" complex, thereby facilitating the subsequent 1,5-metalate shift.
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
Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
Preparation of Alcohols via Addition Reactions
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
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 stereochemistry.
Aldol Condensation with β-Diesters: Knoevenagel Condensation

