A novel synthetic route for making (−)-CBD and its derivatives bearing various C4′-side chains is developed by a late-stage diversification method. Starting from commercially available phloroglucinol, the key intermediate (−)-CBD-2OPiv-OTf is efficiently and regioselectively prepared and further undergoes Negishi cross-coupling to furnish (−)-CBD. This approach allowed an efficient synthesis of (−)-CBD in a five-step total 52% yield on a 10 g scale. Furthermore, diversification on the C4′-side chain with this method can be realized in a wide range.

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Inorganic persulfate salts were identified as efficient reagents for the oxidative aromatization of 3,4-dihydroquinolin-2­(1H)-ones through the activation of readily available transition metals, such as iron and copper. The feasible protocol conforming to the requirement of green chemistry was utilized in the preparation of the key intermediate (7-(4-chlorobutoxy)­quinolin-2­(1H)-one 2) of brexpiprazole in 80% isolated yield on a 100 g scale, and different quinolin-2­(1H)-one derivatives with various functional groups were demonstrated in 52–89% yields.