Issue 19, 2021

Direct oxidative carboxylation of terminal olefins to cyclic carbonates by tungstate assisted-tandem catalysis

Abstract

Tungstate catalysts are well established for olefin epoxidation reactions, while their catalytic activity for CO2 insertion in epoxides is a more recent discovery. This dual reactivity of tungstate prompted the present development of a catalytic tandem process for the direct conversion of olefins into the corresponding cyclic organic carbonates (COCs). Each of the two steps was studied in the presence of the ammonium tungstate ionic liquid catalyst – [N8,8,8,1]2[WO4] – obtained via a benign procedure starting from ammonium methylcarbonate ionic liquids. The catalytic epoxidation first step was optimised on 1-decene as model substrate, using H2O2 as benign oxidant, [N8,8,8,1]2[WO4] as catalyst and phosphoric acid as promoter affording quantitative conversion with 92% selectivity towards decene oxide. Unfortunately, the addition of CO2 from the start (auto-tandem catalysis) gave low yields of decene carbonate (<10%). On the contrary, the addition of 1 atm CO2 and tetrabutyl ammonium iodide after completion of the epoxidation first step without any intermediate work-up (assisted-tandem catalysis) afforded a 94% yield in decene carbonate. The protocol could be scaled up to a 10 gram scale. The scope of the reaction was demonstrated for primary aliphatic olefins with different alkyl chain lengths (C6–C16), while cyclic and aromatic activated olefins such as cyclohexene and styrene suffered from the formation of undesired overoxidation products in the first step.

Graphical abstract: Direct oxidative carboxylation of terminal olefins to cyclic carbonates by tungstate assisted-tandem catalysis

Supplementary files

Article information

Article type
Paper
Submitted
21 iyl 2021
Accepted
10 sen 2021
First published
10 sen 2021

Green Chem., 2021,23, 7609-7619

Direct oxidative carboxylation of terminal olefins to cyclic carbonates by tungstate assisted-tandem catalysis

R. Calmanti, M. Selva and A. Perosa, Green Chem., 2021, 23, 7609 DOI: 10.1039/D1GC02603H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements