Hydrodeoxygenative Cyclotetramerization of Carbon Monoxide by a Trinuclear Titanium Polyhydride Complex

Area of Science:

• Organometallic Chemistry
• Catalysis
• Inorganic Chemistry

Background:

• Reductive coupling of carbon monoxide (CO) is crucial in chemistry.
• Metal hydrides are key catalysts for CO transformations.
• Developing novel catalytic pathways for CO utilization is essential.

Purpose of the Study:

• To report a novel hydrodeoxygenative cyclotetramerization of CO.
• To investigate the reactivity of a trinuclear titanium polyhydride complex with CO.
• To explore the synthesis of value-added chemicals from CO.

Main Methods:

• Reaction of carbon monoxide (CO) with a trinuclear titanium polyhydride complex [(C5Me4SiMe3)Ti]3(μ3-H)(μ2-H)6 at -78 °C.
• Characterization of reaction intermediates including ethen-1,2-diyl and cyclobuten-3,4-diyl-1,2-diolate species.
• Hydrogenolysis and acidolysis of intermediates to yield final products.

Main Results:

• Formation of an ethen-1,2-diyl species via CO dimerization.
• Cycloaddition of CO to form a cyclobuten-3,4-diyl-1,2-diolate unit.
• Conversion of intermediates to tetrahydrocyclobuten-1,2-diolate, cyclobuten-2-yl-1-olate, gamma-butyrolactone, and cyclobutanone.

Conclusions:

• The trinuclear titanium polyhydride complex facilitates unprecedented hydrodeoxygenative cyclotetramerization of CO.
• The study demonstrates a novel pathway for CO conversion into complex organic structures.
• The methodology provides access to valuable chemical feedstocks like gamma-butyrolactone and cyclobutanone.