Pd/C-catalyzed synthesis of oxamates by oxidative cross double carbonylation of alcohols and tertiary amines through C-N bond cleavage

摘要

An efficient synthesis of oxamates by Pd/C-catalyzed oxidative cross double carbonylation of alcohols and unactivated tertiary amines has been demonstrated. The in situ oxidative C-N bond cleavage of tertiary amines was achieved using molecular oxygen as an environmentally benign oxidant providing a user-friendly approach to the synthesis of oxamates. The developed protocol showed excellent activity towards the cyclic as well as aliphatic tertiary amines and long-chain alcohols. This developed protocol system is advantageous, as it is phosphine ligand free, base free, and copper-free and the Pd/C catalyst is easily recyclable. The Pd/C catalyst was recycled up to five consecutive cycles.