Yield:-

Steps:

Multi-step reaction with 7 steps
1.1: triethylamine; dmap / dichloromethane / 14 h / 20 °C
2.1: lithium diisopropyl amide / tetrahydrofuran / 12 h
3.1: trifluoroacetic acid / dichloromethane / 16 h
4.1: trimethoxonium tetrafluoroborate; 2,6-di-tert-butyl-pyridine / dichloromethane / 12 h
4.2: 0.5 h
5.1: [bis(trifluoromethanesulfonyl)imidate](triphenylphosphine)gold(I); 2-bromopyridine-N-oxide; methanesulfonic acid; silver trifluoromethanesulfonate / 5 h / 20 °C
5.2: 3 h / 20 °C
6.1: potassium tert-butylate / tetrahydrofuran / 2 h
7.1: hydrogenchloride; 2,2,2-trifluoroethanol; iron(III) chloride / 2 h
7.2: 0.5 h / 0 °C

References:

Zhang, Yun;Xue, Yibin;Li, Gang;Yuan, Haosen;Luo, Tuoping [Chemical Science,2016,vol. 7,# 8,p. 5530 - 5536]