Related Experiment Video
Updated: Oct 3, 2026

Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
Computational Study of B(4)H(10) Addition to Ethene. Baskets from Boranes
Michael Bühl1, Michael L. McKee
1Department of Chemistry, Auburn University, Auburn, Alabama 36849.
Abstract:
Three pathways leading from B(4)H(10) + C(2)H(4) to (CH(2)CH(2))B(4)H(8) are examined at the [MP4/6-311+G(d,p)]//MP2/6-31G(d) + ZPC level. The preferred, "addition" path involves transient [B(4)H(8)], [B(4)H(8)(C(2)H(4))], and a cage-opened [(CH(2)CH(2))B(4)H(8)] intermediate with a rate-determining barrier of 33.0 kcal/mol (for [B(4)H(8)] formation). "Indirect hydroboration" of ethene via [B(4)H(8)] is disfavored by entropy and can be excluded. "Direct hydroboration" via a higher-energy [B(4)H(10)] isomer can be competitive; the overall energetic barrier for this process is only 26.9 kcal/mol, but the hydroboration step is disfavored by entropy to such an extent that the "addition" path is the main route at the experimental temperatures. Direct hydroboration affords the intermediate Et-B(4)H(9) which is likely to be involved in side reactions leading to byproducts such as Et-(CH(2)CH(2))B(4)H(7).
More Related Videos
07:50Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
09:35Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Related Concept Videos
Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene
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 stereochemistry.
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene
Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control
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.