Related Experiment Video
Updated: Feb 20, 2026
07:36
Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
Published on: November 9, 2019
8.4K
CuOTf-mediated intramolecular diborene hydroarylation
Sunewang Rixin Wang1, Merle Arrowsmith, Holger Braunschweig
1Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. h.braunschweig@uni-wuerzburg.de.
Chemical Communications (Cambridge, England)
|October 21, 2017
Summary
A novel cyclic boronium triflate salt was synthesized from a PMe3-stabilized bis(9-anthryl) diborene. This was achieved through a room-temperature intramolecular hydroarylation reaction and subsequent triflation and phosphine transfer.
Area of Science:
- Organoboron chemistry
- Catalysis
- Organic synthesis
Background:
- Bis(9-anthryl) diborene complexes are known precursors in organometallic chemistry.
- Intramolecular hydroarylation reactions offer pathways to complex cyclic structures.
- Phosphine ligands play crucial roles in stabilizing reactive intermediates.
Purpose of the Study:
- To investigate the reactivity of PMe3-stabilized bis(9-anthryl) diborene.
- To explore the formation of novel cyclic boron compounds.
- To elucidate the mechanism of complexation-induced transformations.
Main Methods:
- Complexation of bis(9-anthryl) diborene with copper(I) triflate (CuOTf).
- Monitoring of the reaction progress via spectroscopic techniques.
- Isolation and characterization of the final product.
Main Results:
- Slow intramolecular hydroarylation of the diborene observed at room temperature upon complexation.
- Triflation of the B-H bond and subsequent PMe3 transfer occurred.
- Formation of a unique cyclic sp2-sp3 boryl-substituted boronium triflate salt.
Conclusions:
- Copper(I) triflate effectively catalyzes the transformation of bis(9-anthryl) diborene.
- The reaction proceeds through a hydroarylation pathway to form a cyclic boronium salt.
- This study introduces a new synthetic route to boryl-substituted cyclic boron compounds.
More Related Videos
Related Concept Videos
03:08Hydroboration-Oxidation of Alkenes
11.7K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
11.7K
02:36Regioselectivity and Stereochemistry of Hydroboration
9.5K
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
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.
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.
9.5K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
21.5K
Introduction
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.
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.
21.5K
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
12.7K
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
12.7K
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
7.6K
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
7.6K
01:18β-Dicarbonyl Compounds via Crossed Claisen Condensations
3.9K
Crossed Claisen condensations are base-promoted reactions between two different ester molecules producing β-dicarbonyl compounds. The reaction involving esters, with both containing α hydrogen, results in a mixture of four different products that are difficult to isolate. This reduces the synthetic utility of the reaction.
3.9K