Aldehydes as CO Releasing Molecules: in-situ and ex-situ Giese Reactions and Palladium Catalyzed Aminocarbonylations

CO releasing molecules (CORMs) are compounds able to release carbon monoxide upon activation. The C1 synthon thus released may be used by valuable in situ or ex situ carbonylations. However, the atom economy of the process is low due to the loss of the remaining part of the CORM that impacted on the eco-sustainability of the reaction. To overcome this limitation, we adopted a two-chambers reactor making use of aliphatic aldehydes in the role of CORMs. Upon photocatalytic conditions, an acyl radical (RCO(dot)) was first formed prone to lose CO. In such a way, the resulting alkyl radical was employed in the in situ conjugate addition onto Michael acceptor (in the first Chamber) and the released CO in ex situ Palladium catalyzed aminocarbonylations (in the second Chamber) to assure a 100% atom economically reaction.