Enantioselective hydrogenation of annulated arenes: controlled formation of multiple stereocenters in adjacent rings†
We report a method for the enantioselective hydrogenation of annulated arenes using 4H-pyrido[1,2-a]pyrimidinones as substrates. The method selectively generates multiple stereocenters in adjacent rings leading to architecturally complex motifs, which resemble bioactive molecules. The mechanistic study of the stereochemical outcome revealed that the catalyst is able to overcome substrate stereocontrol providing all-cis-substituted products predominantly. In a sequential protocol, a matching interaction between catalyst and substrate stereocontrol is achieved that facilitates diastereo- and enantioselective access to trans-products.