abstract
The Mo-IV complex [(eta(5)-indenyl)(eta(5)-cyclopentadienyl)Mo(MeCN)(2)](BF4)(2) (1) has been used to promote two acid-catalyzed epoxide ring-opening reactions under ambient conditions. The alcoholysis of styrene oxide in neat ethanol gave 2-ethoxy-2-phenylethanol in quantitative yield within 10 min. The use of an ionic liquid (IL) as a cosolvent benefitted catalyst solubility and recycling while not impairing catalytic performance. Complex 1 in 1,2-dichloroethane was effective for the isomerization of alpha-pinene oxide to campholenic aldehyde (CPA), leading to 87% yield at 1 h of reaction. The same yield could be achieved within 1 min by using the IL [Choline][NTf2] as a solvent. CPA yields at 1 min reached near-quantitative values (98%) upon recycling of the catalyst/IL mixture, demonstrating an unparalleled combination of activity, selectivity and recyclability for this commercially important reaction. Considering the catalytic features of the 1/IL system, a CPA process flow diagram is proposed and compared to patented technology.
keywords
IONIC LIQUIDS; REARRANGEMENT; CATALYSTS; ACID; EPOXIDATION; SOLVENTS
subject category
Chemistry; Science & Technology - Other Topics; Engineering
authors
Bruno, SM; Valente, AA; Pillinger, M; Arnelse, J; Romao, CC; Goncalves, IS
our authors
Anabela Tavares Aguiar Valente
Principal Researcher
Isabel Maria de Sousa Gonçalves
Associate Professor
Martyn Pillinger
Principal Researcher
Sofia M. Bruno
Assistant ResearcherProjects
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)
Sistemas ativados por estímulos para a terapia com monóxido de carbono (SASCOT)
acknowledgements
This work was carried out with the support of CICECO - Aveiro Institute of Materials [FCT (Fundacao para a Ciencia e a Tecnologia) ref. UID/CTM/50011/2019], and the CENTRO 2020 Regional Operational Programme (Project References CENTRO-01-0145-FEDER-028031 and PTDC/QUI-QOR/28031/2017), cofinanced by national funds through the FCT/MEC and the European Union (EU) through the European Regional Development Fund under the Portugal 2020 Partnership Agreement. The position held by S.M.B. was funded by national funds (OE), through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of article 23 of the Decree-Law 57/2016 of 29 August, changed by Law 57/2017 of 19 July.