Photolabile Carbonyl Protecting Group: A New Tool for Light‐Controlled Release of Anticancer Agents

Abstract

A new type of photolabile carbonyl-protecting group was utilized in releasing anticancer agents upon irradiation at 350 nm in an aqueous environment.

Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy

“…Wang and co-workers developed a photoremovable protecting group for carbonyl compounds based on trityl photochemistry. 320 Ketones and aldehydes are converted into cyclic acetals ( 173 ) by treatment with 5-methoxysalicylic alcohol derivatives (Scheme 69). Upon irradiation, the carbonyl compounds are released in 75–90% yield and good quantum efficiency ( Φ = 0.11).…”

Using the 3-Diethylaminobenzyl Group as a Photocage in Aqueous Solution

“…These PPGs have advantageous features, including (1) their structural simplicity and chemical stability, (2) simple and cost-effective preparation, (3) high efficiency of protection/deprotection, (4) compatibility with ambient conditions (e.g., air and water) during irradiation, and (5) flexible structural modification without compromising photochemical properties, etc. [5][6][7][8][9][10][11]13,14,16 For applications of these PPGs in aqueous solution as photocages, we demonstrated that by incorporating poly(ethylene glycol) 8 or carboxylate side chains, 16 the PPGs can be converted to their corresponding water-soluble counterpart. For instance, the hydrophobic 3-dimethylaminotrityl group (DMATr) PPG for the hydroxyl group was converted to its water-soluble version (as one shown in 1, Scheme 1).…”

“…We have recently developed a series of structurally simple PPGs for releasing carbonyl, 5−12 hydroxyl, 12−17 diol, 18 carboxyl, 15 and amino groups. 19,20 Their applications in organic synthesis, 21 photoactivated prodrugs, 8,22 photorelease of perfumes in solid phase, 23 photocleavage of polymers, 12 light-controlled hydrogel formation, 24 and surface patterning 25 have been explored recently. These PPGs have advantageous features, including (1) their structural simplicity and chemical stability, (2) simple and cost-effective preparation, (3) high efficiency of protection/deprotection, (4) compatibility with ambient conditions (e.g., air and water) during irradiation, and (5) flexible structural modification without compromising photochemical properties, etc.…”

Application of new photolabile protecting groups as photocleavable joints of block copolymers

“…We have recently developed a series of novel PPGs for protection of carbonyl and hydroxyl groups (Scheme 1). [22][23][24][25][26][27][28][29][30][31] For example, a carbonyl compound (1) can be protected by our new PPG reagent 2 and be converted to an acetal/ketal (3), and an alcohol (4) can be protected as an ether by the new PPG reagent 5. Upon UV irradiation, the acetal/ketal 3 and the ether 6 release the carbonyl compound and the alcohol, respectively.…”

“…A three-step sequence of esterification, acetylation, and Grignard reaction provided the salicyl alcohol 8. 24 Its reaction with the aldehyde 9 under the neutral reaction conditions and the subsequent reduction of the amide moiety led to the known acetal 10 in 84% yield (two steps). Treatment of 10 with propargyl bromide followed by 2-bromo-2-methylpropanoyl bromide resulted in the photolinker 11a in 89% yield (two steps).…”