Functional molecules cross-linked via hindered disulfides^a,b.

^aConditions: 1 (0.1 mmol), 2a (0.1 mmol), and DMAP (1.1 equiv.) in CH₂Cl₂ (2 mL) were stirred at room temperature for 12 h; then 4 (1 equiv.), HOBt (1.5 equiv.), EDCI (1.5 equiv.) and DIPEA (2.5 equiv.) were added, and the mixture was stirred at room temperature overnight.

^bIsolated yields.

^cConditions: 1s (0.12 mmol), 2a (0.1 mmol) and DMAP (0.02 mmol) in CH₂Cl₂ (1 mL) were stirred at room temperature for 12 h.