Determined amounts of the reagents, catalyst and additives were charged in a Schlenk flask (under nitrogen). Before heating, the headspace of the flask was filled with a specific ratio of gases (using a balloon and autoclave, see Supplementary Information). Hereafter, the Schlenk flask was immersed in an oil bath to meet the set temperature. Reactions were performed under continuous stirring. Qualitative and quantitative analysis and characterization of reaction mixtures and pure products were performed with GC-MS and NMR.