891-63-4Relevant articles and documents
Phosphate-Based Self-Immolative Linkers for Tuneable Double Cargo Release
?imon, Petr,Tichotová, Markéta,García Gallardo, María,Procházková, Eli?ka,Baszczyňski, Ond?ej
supporting information, p. 12763 - 12775 (2021/08/03)
Phosphorus-based self-immolative (SI) linkers offer a wide range of applications, such as smart materials and drug-delivery systems. Phosphorus SI linkers are ideal candidates for double-cargo delivery platforms because they have a higher valency than carbon. A series of substituted phosphate linkers was designed for releasing two phenolic cargos through SI followed by chemical hydrolysis. Suitable modifications of the lactate spacer increased the cargo release rate significantly, from 1 day to 2 hours or 5 minutes, as shown for linkers containing p-fluoro phenol. In turn, double cargo linkers bearing p-methyl phenol released their cargo more slowly (4 days, 4 hours, and 15 minutes) than their p-fluoro analogues. The α-hydroxyisobutyrate linker released both cargos in 25 minutes. Our study expands the current portfolio of SI constructs by providing a double cargo delivery option, which is crucial to develop universal SI platforms.
Kinetics and mechanism of the aminolysis of phenyl substituted phenyl chlorophosphates with anilines in acetonitrile
Guha, Arun Kanti,Lee, Hai Whang,Lee, Ikchoon
, p. 765 - 769 (2007/10/03)
The kinetics and mechanism of the aminolysis of phenyl substituted phenyl chlorophosphates with anilines are investigated in acetonitrile at 55.0°C. Very sensitive variation of ρY (δρY ? 0) with the change of substituent on the nucleophile (δσX) leads to a large negative cross-interaction constant, ρXY = (δρY)/(δσX) = -1.31. The secondary kinetic isotope effects observed with deuterated aniline nucleophiles are of the inverse type (kH/kD = 0.61-0.87), and small ΔH? (1.6-9.7 kcal mol-1) and large negative ΔS? (-43 to -65 e.u.) values are obtained. These results are consistent with a concerted process with a late, product-like transition state in which both bond making and leaving group departure are extensive.