Related Experiment Video
Updated: Jul 9, 2026
07:06
Continuous Flow Chemistry: Reaction of Diphenyldiazomethane with p-Nitrobenzoic Acid
Published on: November 15, 2017
"Solventless" continuous flow homogeneous hydroformylation of 1-octene
Anja C Frisch1, Paul B Webb, Guoying Zhao
1EaStCHEM, School of Chemistry, University of St. Andrews, St. Andrews, Fife, UKKY16 9ST.
Dalton Transactions (Cambridge, England : 2003)
|November 29, 2007
Summary
This study optimized the hydroformylation of 1-octene using supercritical CO2 and rhodium catalysts. The [OMIM][TPPMS] ligand achieved high reaction rates and low rhodium losses, demonstrating an efficient continuous flow process.
Area of Science:
- Catalysis
- Green Chemistry
- Chemical Engineering
Background:
- Continuous flow hydroformylation offers advantages over batch processes.
- Supercritical CO2 (scCO2) is an environmentally friendly solvent for chemical reactions.
- Rhodium-based catalysts are highly active for hydroformylation but prone to leaching.
Purpose of the Study:
- To develop and optimize a continuous flow hydroformylation system for 1-octene using scCO2.
- To evaluate different rhodium-ligand systems, specifically [RMIM][TPPMS] (R=Pr, Pn, O), for activity, selectivity, and catalyst stability.
- To minimize rhodium leaching and maximize catalyst efficiency under process conditions.
Main Methods:
- In situ catalyst preparation using [Rh(acac)(CO)2] and various [RMIM][TPPMS] ligands.
- Hydroformylation of 1-octene in a continuous flow reactor using scCO2 as the solvent.
- System optimization involving control of CO/H2 and substrate flows, pressure, and temperature.
- Analysis of rhodium leaching using inductively coupled plasma mass spectrometry (ICP-MS).
Main Results:
- The [OMIM][TPPMS] ligand demonstrated the highest solubility and promoted high reaction rates.
- Optimized conditions using [OMIM][TPPMS] at 140 bar achieved a turnover frequency of approximately 180 h-1 with rhodium losses as low as 100 ppb.
- [PrMIM][TPPMS] showed poor solubility and significant rhodium leaching, while [PnMIM][TPPMS] led to catalyst precipitation at higher loadings.
- Transport studies indicated preferential transport of 1-octene over aldehydes, with extraction efficiency influenced by pressure and mobile phase composition.
Conclusions:
- The continuous flow hydroformylation of 1-octene in scCO2 is feasible and can be highly efficient.
- [OMIM][TPPMS] is a suitable ligand for achieving high activity and low rhodium leaching in this system.
- Process parameters, including ligand choice, pressure, and flow rates, are critical for optimizing hydroformylation performance and catalyst stability.
Related Concept Videos
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...
03:08Hydroboration-Oxidation of Alkenes
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.
01:28Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
01:27Benzene to Phenol via Cumene: Hock Process
The synthesis of phenol from benzene via cumene and cumene hydroperoxide is called the Hock process. First, a Friedel–Crafts alkylation reaction of benzene with propene gives cumene. Then cumene forms cumene hydroperoxide via a radical chain reaction. In the chain initiation step, the benzylic hydrogen is abstracted to give a benzylic radical. In the chain propagation step, the benzylic radical reacts with an oxygen diradical to form a cumene hydroperoxide radical. The cumene hydroperoxide...
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...
02:41Formation of Halohydrin from Alkenes
An alkene, such as propene, reacts with bromine in the presence of water to yield a halohydrin. Halohydrins contain a halogen and a hydroxyl group attached to adjacent carbons. When the halogen is bromine, it is called a bromohydrin, while a chlorohydrin has chlorine as the halogen.