One-Pot High-Yielding Synthesis of the DPP4-Selective Inhibitor ABT-341 by a Four-Component Coupling Mediated by a Diphenylprolinol Silyl Ether

A dream come true: ABT‐341 was synthesized in high yield with excellent diastereo‐ and enantioselectivity in a one‐pot process mediated by a diphenylprolinol silyl ether (see scheme; TMS=trimethylsilyl). Thus, an asymmetric Michael reaction, a domino Michael/Horner–Wadsworth–Emmons reaction combined with a retro‐aldol reaction, base‐catalyzed isomerization, amide‐bond formation, and reduction of the nitro group all took place in a single flask.