Application of Nanoscale Zwitterionic Polyelectrolytes Brush with High Stability and Quantum Yield in Aqueous Solution for Cell Imaging

Scheme 2

The synthetic routes toward P4. Reagents and conditions: (i) (1) n-BuLi, THF, -78 ^oC, 2 h; (2) triisopropyl borate, room temperature, 12 h; (3) 1,3-propanediol, toluene, reflux, 10 h; (ii) 3-bromo-1-propanol, tetrabutylammonium bromide, NaOH/H₂O, DMSO, 85°C, 24 h; (iii) Pd(PPh₃)₄, K₂CO₃, toluene/H₂O, 90°C, 72 h; (iv) 2-bromoisobutyryl bromide, N(Et)₃, 24 h; (v) CuBr, HMTETA, DMAEMA, 90°C, 12 h; (vi) 1,3-propanesultone, acetonitrile, room temperature, 36 h.