Regio- and Stereoselective Palladium-Catalyzed C(sp)-H Arylation of Pyrrolidines and Piperidines with C(3) Directing Groups.

The selective synthesis of cis-3,4-disubstituted pyrrolidines and piperidines is achieved by a Pd-catalyzed C-H arylation with excellent regio- and stereoselectivity using an aminoquinoline auxiliary at C(3). The arylation conditions are silver free, use a low catalyst loading, and employ inexpensive KCO as a base. Directing group removal is accomplished under new, mild conditions to access amide-, acid-, ester-, and alcohol-containing fragments and building blocks. This C-H arylation protocol enabled a short and stereocontrolled formal synthesis of (-)-paroxetine.