Rh(III)-catalyzed C-H allylation/annulative Markovnikov addition with 5-methylene-1,3-dioxan-2-one: formation of isoquinolinones containing C3 quaternary centre

The Rh(III)-catalyzed synthesis of isoquinolinones containing C3 quaternary centre via a tandem C-H allylation/annulative Markovinkov addition reaction has been achieved. This method employing a single Rh(III) complex as the catalyst tolerated various functional groups, and was viable to late-stage diversification of N-methoxyamides derived from steroids and Adapalene. By applying the protocol as the key step, the US28 inverse agonist analogs were conveniently synthesized.