Related Experiment Video
Updated: Aug 5, 2026
08:12
Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance
Published on: September 5, 2018
Pd/Mo-Catalyzed ortho-Dihydroxylation of Aromatic Rings: Dual-Metal-Mediated C(sp2)-H Functionalization
Dingmei Hu1, Renfeng Du1,2, Yongtao Wang1,2
1Zhejiang Key Laboratory of Low-Carbon Synthesis of Value-Added Chemicals, Department of Chemistry, Zhejiang University, 866 Yuhangtang Rd, Hangzhou310058, China.
Journal of the American Chemical Society
|July 30, 2026
Summary
This study introduces a direct ortho-dihydroxylation method for benzoic acids using a palladium/molybdenum catalyst and tert-butyl hydroperoxide (TBHP). This efficient process provides a concise route to valuable meta-diphenolic compounds.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Benzoic acids are key precursors in organic synthesis.
- Directing ortho-dihydroxylation of benzoic acids is synthetically challenging.
- Multistep industrial processes are typically required for meta-diphenolic compounds.
Purpose of the Study:
- To develop a direct ortho-dihydroxylation protocol for benzoic acids.
- To investigate the role of a Pd/Mo bimetallic catalyst in the dihydroxylation reaction.
- To establish a concise synthetic route to meta-diphenolic compounds.
Main Methods:
- Utilized a palladium/molybdenum (Pd/Mo) bimetallic catalyst.
- Employed tert-butyl hydroperoxide (TBHP) as the oxidant.
- Conducted mechanistic studies including radical inhibition, spectroscopy, and substituent effects.
Main Results:
- Achieved direct ortho-dihydroxylation of benzoic acids.
- Demonstrated that the Mo component enhances the second hydroxylation step.
- Showed that monohydroxylation can be achieved by controlling TBHP concentration.
- Confirmed practicality through gram-scale reactions and derivatizations.
Conclusions:
- The Pd/Mo bimetallic system provides an efficient method for ortho-dihydroxylation.
- The mechanism involves Mo facilitating a radical-generating step.
- The method offers a concise route to meta-diphenolic compounds via decarboxylation.
![[(DPEPhos)(bcp)Cu]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)
Related Concept Videos
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
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...
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
02:36Regioselectivity and Stereochemistry of Hydroboration
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.
01:13Olefin Metathesis Polymerization: Overview
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
![[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
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.