In the presence of a catalytic amount of organic bases, Pd-catalyzed transfer hydrogenations with formic acid were found to be facile processes. These new conditions produce innocuous carbon dioxide as the by-product compared to the use of ammonium formate, which generates ammonia and carbon dioxide as gaseous by-products which recombine to create unsafe conditions. When the substrate is basic enough to form salts with formic acid, no additional base is necessary. In certain cases, the product of the reaction was used to accelerate the transfer hydrogenation process.
A new method for N-methylation of indoles using environmentally safe and less toxic methylating reagent, dimethyl carbonate (DMC), has been developed. The effect of various functional groups on the indole ring has been investigated. This method provides the desired product in high yields with high purity and is suitable for large-scale production. This process was used successfully in a 300-gal reactor train for N-methylation of 6-nitroindole.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.