20525-37-5

Upstream product

• 872-05-9 1-Decene 
• 67-56-1 methanol 

Downstream Products

• 124-19-6 nonan-1-al 
• 112-05-0 nonanoic acid 
• 64935-40-6 (E)-2-heptyl-3-octylacrolein 

Relevant academic research and scientific papers

Highly efficient biphasic ozonolysis of alkenes using a high-throughput film-shear flow reactor

A new method for ozonolysis of alkenes using a continuous flow film-shear reactor was developed. The reactor uses a shearing microfluidic mixing chamber to provide biphasic mixing of an organic phase and aqueous phase with ozone gas. The H2O acts as an in situ reducing agent for the carbonyl oxide intermediate, providing ketones and aldehydes directly from the reaction mixture. Flow rates of up to 1.0 mmol/min (alkene) with an ozone reaction efficiency of >70% were achieved. Aryl conjugated olefins reacted to form carbonyl species in good yields on a multi-gram scale; however, alkyl olefins reacted with ozone to predominantly form secondary ozonides. The discrepancy in product distributions between alkyl and aryl olefins likely originates from the electronic stability of the carbonyl oxide intermediate, which is longer lived for aryl derivatives due to conjugation.

Ozonolysis in flow using capillary reactors

Reactions of n-decene with ozone and subsequent quenching of the formed ozonides were carried out under flow conditions using the standard Vapourtec flow system equipped with a cooled flow cell. The reactions were performed continuously and in the annular flow regime within the circular cross-section channels. Typical flow rates were 0.25-1 mL min-1 for liquid and 25-100 mL min-1 for gas, reactor volumes were 0.07-10 mL formed of 1 mm ID PFA tubing. The reaction temperature was -10 °C. The flow was not always smooth, while waves in the liquid film and droplets in the gas core were observed. Liquid residence times were found to be independent of gas flow rates and increasing with decreasing liquid flow rates. Substrate residence times in the ozonolysis reactor ranged between 1 and 80 s, and complete conversion could be achieved at ～1 s residence time. Two common reductants, triethylphosphite and triphenylphosphine, were examined as to their suitability under flow conditions. Triphenylphosphine achieved faster reduction of the intermediate ozonides, resulting in a greater than 10:1 selectivity for the aldehyde over the corresponding acid. The cooling system provided a safe and efficient control of the highly exothermic reaction system. The configuration of the system allowed the production of chemically significant amounts (1.8 g h-1 at 1.3 ozone equivalents), with minimal amounts of ozonides present at any time.

'Reductive ozonolysis' via a new fragmentation of carbonyl oxides

This account describes the development of methodologies for 'reductive' ozonolysis, the direct ozonolytic conversion of alkenes into carbonyl groups without the intermediacy of 1,2,4-trioxolanes (ozonides). Ozonolysis of alkenes in the presence of DMSO produces a mixture of aldehyde and ozonide. The combination of DMSO and Et3N results in improved yields of carbonyls but still leaves unacceptable levels of residual ozonides; similar results are obtained using secondary or tertiary amines in the absence of DMSO. The influence of amines is believed to result from conversion to the corresponding N-oxides; ozonolysis in the presence of amine N-oxides efficiently suppresses ozonide formation, generating high yields of aldehydes. The reactions with amine oxides are hypothesized to involve an unprecedented trapping of carbonyl oxides to generate a zwitterionic adduct, which fragments to produce the desired carbonyl group, an amine, and 1O2.

Fragmentation of carbonyl oxides by N-oxides: An improved approach to alkene ozonolysis

Ozonolysis of alkenes in the presence of amine N-oxides results in the direct formation of aldehydes. This reaction, which appears to involve an unprecedented trapping and fragmentation of the short-lived carbonyl oxide intermediates, avoids the hazards associated with generation and isolation of ozonides or other peroxide products.

OZONOLYSIS OF OLEFINS AND ACETYLENES ADSORBED ON SILICA GEL

Ozonation of phenyl ethylenes adsorbed on untreated silica gel results in aromatic aldehydes and on dried silica gel in ozonides and aldehydes.On the other hand ozonation of alkyl ethylenes on both types of silica gel results in a mixture of ozonides or polymeric peroxides similar to that obtained in aprotic solvents.