Scheme 2.

Synthesis of the triazolyl-cyclam/F-BODIPY conjugates 3 (A) and 4 (B). Reagents and conditions: (a) (i) 2,4-dimethyl-1H-pyrrole (5), TFA, DCM, rt, overnight; (ii) DDQ, rt, 2 h; (iii) Et₃N, BF₃·OEt₂, rt, overnight, 27%; (b) NH₂NH₂·H₂O, 10% Pd/C, EtOH, reflux, 2 h, 90%; (c) (i) 1 M HCl (aq), CH₃OH, NaNO₂, H₂O, 0 °C, 1 h; (ii) NaN₃, H₂O, rt, 2 h, 71%; (d) propargyl-tri-Boc cyclam 12, CuSO₄·5H₂O, sodium ascorbate, THF/H₂O (7:3), 50 °C, 12 h, 100%; (e) trimethylsilylacetylene, CuI, Pd(PPh₃)₄, Et₃N, THF, rt, overnight, 100%; (f) K₂CO₃, CH₃OH, rt, overnight, 71%; (g) (i) 2,4-dimethyl-1H-pyrrole (5), TFA, DCM, rt, overnight; (ii) DDQ, rt, 2 h; (iii) Et₃N, BF₃·OEt₂, rt, overnight, 24%; (h) 2-azidoethyl-tri-Boc cyclam 13, CuSO₄·5H₂O, sodium ascorbate, THF/H₂O (7:3), 50 °C, 12 h, 91%.