Rh(III)-catalyzed CH activation/intramolecular annulation for the synthesis of N-methoxydihydropyrimidin-2-one fused heterocycles

A facile rhodium-catalyzed CH activation/intramolecular annulation strategy for N-methoxydihydropyrimidin-2-one was well realized in water media. Moreover, this Rh(III)-catalytic system facilitated the construction of N-methoxydihydropyrimidin-2-one scaffolds reminiscent of unnatural amino alcohols, transformation to pyran-2-one fused heterocycles as well as late-stage modification of drug molecules. Also, the protocol was easily scaled up to a gram-scale level. And H2O was proposed to act as an alternative coordination molecule to accelerate the generation of active Rh(III) catalyst species.