Halcon process

In chemistry, the '''Halcon process''' refers to technology for the production of propylene oxide by oxidation of propylene with tert-butyl hydroperoxide. The reaction requires metal catalysts, which typically contain molybdenum:<ref name=Patai /> :(CH₃)₃COOH + CH₂=CHCH₃ → (CH₃)₃COH + CH₂OCHCH₃ The byproduct tert-butanol is recycled or converted to other useful compounds. The process once operated at the scale of >2 billion kg/y.

The lighter analogue of propylene oxide, ethylene oxide, is produced by silver-catalyzed reaction of ethylene with oxygen. Attempts to implement this relatively simple technology to the conversion of propylene to propylene oxide fail. Instead only combustion predominates. The problems are attributed to the sensitivity of allylic C-H bonds.

==Mechanism== The oxidation is thought to proceed by formation of Mo(η²-O₂-tert-Bu) complexes. The peroxy O center is rendered highly electrophilic, leading to attack on the alkene.<ref name=Mechanism />

==History== The Halcon process was developed by Halcon International.<ref name=Society />

==References== <references> <ref name=Society>{{cite journal |doi=10.1021/cen-v059n007.p016|title=Ralph Landau wins 1981 Perkin Medal|year=1981|last1=Fallwell|first1=William|journal=Chemical & Engineering News Archive|volume=59|issue=7|page=16}}</ref> <ref name=Mechanism>{{cite journal |doi=10.1016/0920-5861(87)80012-3|title=D⁰ [''sic''] metal peroxides as homolytic and heterolytic oxidative reagents. Mechanism of the Halcon Epoxidation Process|year=1987|last1=Mimoun|first1=Hubert|journal=Catalysis Today|volume=1|issue=3|pages=281–295}}</ref> <ref name=Patai>{{cite book |title=Peroxides|chapter= Syntheses and Uses of Hydroperoxides and Dialkylperoxides |editor1-first= Saul |editor1-last= Patai | first= Roger&nbsp;A. |last=Sheldon |year= 1983 |publisher= John Wiley & Sons |doi= 10.1002/9780470771730.ch6|series=Chemistry of Functional Groups}}</ref> </references>

Category:Catalysis

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