Scalable Formal Synthesis of (−)-Quinocarcin

A scalable and unified strategy is described for the synthesis of (−)-quinocarcin, an important tetrahydroisoquinoline antitumor alkaloid. The strategy allows the practical formal synthesis of (−)-quinocarcin in 13 steps and 4.8% overall yield using N-phthaloyl-l-alanine as a chiral pool. It features the gram-scale and stereoselective synthesis of the tetrahydroisoquinoline moiety (AB ring) via Pd-catalyzed C(sp3)–H arylation and Pictet–Spengler condensation and a Cu(I)-catalyzed exo-selective [C + NC + CC] coupling reaction to generate the chiral pyrrolidine motif (D ring).