In industrial chemistry, carboalkoxylation is a process for converting alkenes to esters. This reaction is a form of carbonylation. A closely related reaction is hydrocarboxylation, which employs water in place of alcohols.
A commercial application is the carbomethoxylation of ethylene to give methyl propionate:[1]
- C2H4 + CO + MeOH → MeO2CC2H5
The process is catalyzed by Pd[C6H4(CH2PBu-t)2]2. Under similar conditions, other Pd-diphosphines catalyze formation of polyethyleneketone.
Methyl propionate ester is a precursor to methyl methacrylate, which is used in plastics and adhesives.[2]
Carboalkoxylation has been incorporated into various telomerization schemes. For example carboalkoxylation has been coupled with the dimerization of 1,3-butadiene. This step produces a doubly unsaturated C9-ester:[3][4]
- 2 CH2=CH−CH=CH2 + CO + CH3OH → CH2=CH(CH2)3CH=CHCH2CO2CH3
Hydroesterification
editRelated to carboalkoxylation is hydroesterification, the insertion of alkenes and alkynes into the H-O bond of carboxylic acids. Vinyl acetate is produced industrially by the addition of acetic acid to acetylene in the presence of zinc acetate catalysts:[5] Presently, zinc acetate is used as the catalyst:
- CH3CO2H + C2H2 → CH3CO2CHCH2
Further reading
edit- Schoenberg, A.; Bartoletti, I.; Heck, R. F. (1974). "Palladium-catalyzed carboalkoxylation of aryl, benzyl, and vinylic halides". The Journal of Organic Chemistry. 39 (23): 3318–3326. doi:10.1021/jo00937a003.
References
edit- ^ Ahmad, Shahbaz; Bühl, Michael (2021-08-04). "Computational modelling of Pd-catalysed alkoxycarbonylation of alkenes and alkynes". Physical Chemistry Chemical Physics. 23 (30): 15869–15880. Bibcode:2021PCCP...2315869A. doi:10.1039/D1CP02426D. hdl:10023/23678. ISSN 1463-9084. PMID 34318843. S2CID 236472958.
- ^ Scott D. Barnicki (2012). "Synthetic Organic Chemicals". In James A. Kent (ed.). Handbook of Industrial Chemistry and Biotechnology (12th ed.). New York: Springer. ISBN 978-1-4614-4259-2.
- ^ J. Grub; E. Löser (2012). "Butadiene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a04_431.pub2. ISBN 978-3527306732.
- ^ Kiss, Gabor (2001). "Palladium-Catalyzed Reppe Carbonylation". Chemical Reviews. 101 (11): 3435–3456. doi:10.1021/cr010328q. PMID 11840990.
- ^ Bienewald, Frank; Leibold, Edgar; Tužina, Pavel; Roscher, Günter (2019). "Vinyl Esters". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. pp. 1–16. doi:10.1002/14356007.a27_419.pub2. ISBN 9783527303854.