Related Experiment Video
Updated: Mar 2, 2026
08:56
Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
3.5K
Oxoborane (RBO) Complexation and Concomitant Electrophilic Bond Activation Processes
Anindya K Swarnakar1, Christian Hering-Junghans1, Michael J Ferguson1
1Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|May 17, 2017
Summary
New oxoborane complexes featuring short boron-oxygen bonds were synthesized. These Lewis acidic compounds activate strong chemical bonds, acting as inorganic carbon monoxide surrogates.
Area of Science:
- Inorganic Chemistry
- Organometallic Chemistry
- Materials Science
Background:
- Oxoboranes are compounds containing boron-oxygen bonds.
- Understanding the reactivity of boron-oxygen bonds is crucial for developing new chemical transformations.
- Lewis acidic compounds play vital roles in catalysis and synthesis.
Purpose of the Study:
- To synthesize and characterize novel donor-acceptor complexes of oxoboranes.
- To investigate the Lewis acidic properties and reactivity of these encapsulated oxoboranes.
- To explore their potential as synthetic surrogates for the [BO]+ cation.
Main Methods:
- Synthesis of donor-acceptor complexes involving ClB=O and HOB=O.
- Spectroscopic characterization of the synthesized complexes.
- Evaluation of their ability to activate C-F and Si-O bonds.
Main Results:
- Successful synthesis of oxoborane donor-acceptor complexes with short B=O linkages.
- Demonstration of retained high Lewis acidity in the encapsulated oxoboranes.
- Evidence of C-F and Si-O bond activation and functionalization capabilities.
Conclusions:
- The synthesized oxoborane complexes are stable and exhibit significant Lewis acidity.
- These compounds serve as effective synthetic surrogates for the [BO]+ cation, analogous to CO.
- The findings open new avenues for utilizing oxoboranes in chemical synthesis and materials science.
Related Concept Videos
03:08Hydroboration-Oxidation of Alkenes
11.8K
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.
11.8K
02:36Regioselectivity and Stereochemistry of Hydroboration
9.6K
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.
9.6K
02:35Regioselectivity of Electrophilic Additions-Peroxide Effect
11.3K
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
11.3K
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
7.8K
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
7.8K
01:17Radical Anti-Markovnikov Addition to Alkenes: Mechanism
4.9K
The reaction of hydrogen bromide with alkenes in the presence of hydroperoxides or peroxides proceeds via anti-Markovnikov addition. The radical chain reaction comprises initiation, propagation, and termination steps.
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy...
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy...
4.9K
02:15Preparation of Alcohols via Addition Reactions
7.9K
Overview
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...
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...
7.9K