Rhodium-Catalyzed Formylation of Aryl Halides with CO 2 and H 2 .

Authors :: Liu Z
Yang Z
Yu B
Yu X
Zhang H
Zhao Y
Yang P
Liu Z
Source :: Organic letters [Org Lett] 2018 Sep 07; Vol. 20 (17), pp. 5130-5134. Date of Electronic Publication: 2018 Aug 13.
Publication Year :: 2018
Abstract: The reductive formylation of aryl iodides/bromides to aryl aldehydes using CO <subscript>2</subscript> /H <subscript>2</subscript> is presented for the first time. It was realized over a catalytic system composed of RhI <subscript>3</subscript> or RhI <subscript>3</subscript> /Pd(dppp)Cl <subscript>2</subscript> (dppp = 1,3-bis(diphenyphosphino)propane) and PPh <subscript>3</subscript> in the presence of Ac <subscript>2</subscript> O/Et <subscript>3</subscript> N at 100 °C, affording aromatic aldehydes in good to excellent yields, together with good functional-group tolerance and broad substrate scope. The reaction proceeds through three cascade steps, involving HCOOH formation, CO release, and formylation of aryl halides.