skip to main content


This content will become publicly available on April 16, 2019

Title: Iodine-Catalyzed Isomerization of Dimethyl Muconate

cis,cis-Muconic acid is a platform biobased chemical that can be upgraded to drop-in commodity and novel monomers. Among the possible drop-in products, dimethyl terephthalate can be synthesized via esterification, isomerization, Diels-Alder cycloaddition, and dehydrogenation. The isomerization of cis,cis-dimethyl muconate ( ccDMM) to the trans,trans-form ( ttDMM) can be catalyzed by iodine; however, studies have yet to address (i) the mechanism and reaction barriers unique to DMM, and (ii) the influence of solvent, potential for catalyst recycle, and recovery of high-purity ttDMM. To address this gap, we apply a joint computational and experimental approach to investigate iodine-catalyzed isomerization of DMM. Density functional theory calculations identified unique regiochemical considerations due to the large number of halogen-diene coordination schemes. Both transition state theory and experiments estimate significant barrier reductions with photodissociated iodine. Solvent selection was critical for rapid kinetics, likely due to solvent complexation with iodine. Under select conditions, ttDMM yields of 95% were achieved in <1 h with methanol, followed by high purity recovery (>98%) with crystallization. Lastly, post-reaction iodine can be recovered and recycled with minimal loss of activity. Altogether, these findings provide new insight into the mechanism and conditions necessary for DMM isomerization with iodine to advance the state-of-the-art formore » biobased chemicals.« less
ORCiD logo [1] ;  [2] ;  [2] ; ORCiD logo [2] ;  [2] ; ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [2] ; ORCiD logo [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States); Colorado School of Mines, Golden, CO (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1864-5631
Grant/Contract Number:
AC36-08GO28308; SC000997
Accepted Manuscript
Journal Name:
Additional Journal Information:
Journal Volume: 11; Journal ID: ISSN 1864-5631
ChemPubSoc Europe
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
09 BIOMASS FUELS; platform chemicals; reaction mechanism; green chemistry; biomass conversion
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1436543