Fig. 4: Synthetic synergy.
From: Synthesis of dienes from pyrrolidines using skeletal modification
a N-Removal and deconstruction of bioactive compounds. b A sequence of amine-directed C–H functionalization and N-removal and deconstruction reactions. c Formal N-deletion process of pyrrolidines. Standard conditions-I (SC-I): pyrrolidine a (0.2 mmol), DBU (0.4 mmol), N3SO2N3 (0.2 M in DCM, 3.0 mL), DCM (0.5 mL), rt, 3 h; then tBuOLi (1.0 equiv), DCE (2 mL), 120 °C, 3 h, isolated yield of diene based on pyrrolidine. Seidel’s protocol: nBuLi (2.0 equiv), Et2O, −78 °C, 10 min; PhCOCF3 (1.2 equiv), −78 °C, 10 min; RMgBr (1.5 equiv), −78 °C; TMSOTf (1.2 equiv), −78 °C to rt, overnight. Yoon’s protocol: Ir(dF(CF3)ppy)2(dtbbpy)(PF6) (1.0 mol%), diene (0.2 mmol), DMSO, rt, hv, 12 h. aUsing pyrrolidine•HCl instead of pyrrolidine, DBU (0.6 mmol). bYield for the step of C–H functionalization. cYield for the reduction step of the original double bond. dGram scale preparation of the diene (45b).
