Favoring alkane primary carbon-hydrogen bond functionalization in supercritical carbon dioxide as reaction medium

The selectivity of a catalytic alkane functionalization process can be modified just changing the reaction medium from neat alkane to supercritical carbon dioxide (scCO2). A silica supported copper complex bearing an Nheterocyclic carbene ligand promotes the functionalization of carbon-hydrogen bond...

Full description

Bibliographic Details
Authors: Sarmiento, Jeymy T., Olmos Verge, Andrea, Rodríguez Belderraín, Tomás, Caballero Bevia, Ana, Varea, Teresa, Pérez Romero, Pedro José, Asensio, Gregorio
Format: article
Publication Date:2019
Country:España
Institution:Universidad de Huelva (UHU)
Repository:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Language:English
OAI Identifier:oai:ariasmontano.uhu.es:10272/16027
Online Access:http://hdl.handle.net/10272/16027
Access Level:Open access
Keyword:Alkane
Carbon-hydrogen
Carbon dioxide
Description
Summary:The selectivity of a catalytic alkane functionalization process can be modified just changing the reaction medium from neat alkane to supercritical carbon dioxide (scCO2). A silica supported copper complex bearing an Nheterocyclic carbene ligand promotes the functionalization of carbon-hydrogen bonds of alkanes by transferring the CHCO2Et group from N2=CHCO2Et (ethyl diazoacetate, EDA). In neat hexane only 3% of the primary C-H bonds (ethyl heptanoate being the product) are functionalized in that manner, whereas the same reaction carried out in scCO2 provides a 30% yield in this linear ester. Such effect seems to be induced by an electronic density flux from the NHC ligand to the surrounding carbon dioxide molecules.