[4 + 4]-cycloaddition of isoprene for the production of high-performance bio-based jet fuel

Abstract

Bio-based isoprene is converted to a high performance jet fuel blendstock by Fe-catalyzed [4 + 4] cycloaddition and hydrogenation.

Bio‐Based Cycloalkanes: The Missing Link to High‐Performance Sustainable Jet Fuels

“…To generate a higher density blendstock from isoprene, Harvey and co-workers explored the use of reduced iron pyridineimine catalysts for the selective [4 + 4]-cycloaddition of isoprene to generate primarily 1,6-dimethyl-1,5-cyclooctadiene (1,6-DMCOD, 32). [18] This approach was based on seminal work by Chirik that demonstrated selective [4 + 4]cycloadditions with a variety of conjugated dienes. [335] With precatalyst loadings as low as 0.025 mol % [Fe], the dimerization of isoprene proceeded with 98 % conversion and 97 % selectivity to [4 + 4]-products under ambient conditions (neat, RT, 24 h).…”

“…These values are up to 2.4 % and 9 % higher, respectively, than conventional jet fuel (Table 10). [18] In addition to C 5 and C 6 alkenes, Harvey and co-workers recently demonstrated the use of bio-based octadienes as substrates for the preparation of high density cyclic fuels. [336] Linoleic acid is a primary component of safflower, sunflower, grapeseed, corn, and soybean oil that can be oxidatively cleaved by mushroom enzymes to generate primarily 1octen-3-ol and 10-oxo-8-decenoic acid (ODA).…”

“…To generate a higher density blendstock from isoprene, Harvey and co‐workers explored the use of reduced iron pyridineimine catalysts for the selective [4+4]‐cycloaddition of isoprene to generate primarily 1,6‐dimethyl‐1,5‐cyclooctadiene (1,6‐DMCOD, 32 ) [18] . This approach was based on seminal work by Chirik that demonstrated selective [4+4]‐cycloadditions with a variety of conjugated dienes [335] .…”

“…[9][10][11] Other approaches include alcohol-to-jet (ATJ), which is based on the conversion of bio-based alcohols (e. g., ethanol, butanol) to alkenes, followed by oligomerization and hydrogenation. [12][13][14][15][16][17][18][19] Direct sugar to hydrocarbon (DSH) approaches focus on the biosynthetic conversion of biomass sugars to hydrocarbons (e. g., terpenes) via fermentation with metabolically engineered microorganisms. [20][21][22][23] The acyclic HEFA, FT, ATJ, and DSH jet fuels meet most of the requirements of conventional jet fuel, but exhibit lower densities and volumetric heats of combustion.…”

“…Another approach, that can take advantage of lignocellulosic feedstocks and solid municipal waste, is the conversion of biomass substrates to synthesis gas (a mixture of CO and H 2 ) followed by Fischer‐Tropsch catalysis and isomerization to generate an SPK [9–11] . Other approaches include alcohol‐to‐jet (ATJ), which is based on the conversion of bio‐based alcohols (e. g., ethanol, butanol) to alkenes, followed by oligomerization and hydrogenation [12–19] . Direct sugar to hydrocarbon (DSH) approaches focus on the biosynthetic conversion of biomass sugars to hydrocarbons (e. g., terpenes) via fermentation with metabolically engineered microorganisms [20–23] .…”