Enantioselective Synthesis of α-All-Carbon Quaternary Center-Containing Carbazolones via Amino-palladation/Desymmetrizing Nitrile Addition Cascade

An enantioselective Pd(II)-catalyzed amino-cyclization and desymmetrizing nitrile addition cascade reaction of alkyne-tethered malononitriles is reported. This reaction forms two rings and one quaternary carbon center in a single step and serves as an efficient strategy for the construction of alpha-quaternary carbazolones with high enantioselectivities (up to 98:2 er). The utility of this method is demonstrated by product derivatization into a diverse array of heterocycles and a nitrile-containing leucomidine A analog.

Automated summary

This research presents an efficient enantioselective Pd(II)-catalyzed cascade reaction for the transformation of alkyne-tethered malononitriles into alpha-quaternary carbazolones with high enantioselectivities. The utility of this method is demonstrated by the synthesis of diverse heterocycles and a nitrile-containing leucomidine A analog from the obtained products.