Post‐Assembly Photomasking of Potassium Acyltrifluoroborates (KATs) for Two‐Photon 3D Patterning of PEG‐Hydrogels

Abstract

In memory of our colleague and friend Professor François Diederich Chemical ligation reactions of functional groups that can be masked with two-photon labile protecting groups provide a powerful technology for the three-dimensional patterning of molecules-including proteinsonto hydrogel scaffolds. In order to utilize readily prepared hydrogels constructed by the potassium acyltrifluoroborate (KAT)-hydroxylamine amide formation ligation for two-photon patterning, we have developed a unique post-polymerization protecting group strategy through the reaction of KATs and dithiols in water and deprotection by two-photon excitation. After precise 3D spatially confined light irradiation, the unprotected KATs undergo ligations with hydroxylamine-functionalized superfolder GFP and sulforhodamine B for the composition of three-dimensional patterns.

Design and Synthesis of New α-hydroxy β-fluoro/β-trifluoromethyl and Unsaturated Phosphonates from Carbohydrate-Derived Building Blocks via Pudovik and Horner–Wadsworth–Emmons Reactions

“…Examples of use of, weak bases such as K 2 CO 3 , Et 3 N, and NaH to abstract acidic protons from dimethyl malonate or chloroacetone can be found in the literature. [ 65 , 66 , 67 , 68 ] Thus, the obtained calculated results of pK a values of 13 and 19b correlate with experimental observations, in which under the reaction conditions the abstraction of acidic proton can be observed in the first step of the reaction.…”

Dynamic Amide Formation by Reversible Nitrone Exchange of Potassium Acyltrifluoroborates (KATs) and Hydroxylamines in Aqueous Conditions

“…Potassium Acyltrifluoroborates (KATs) are a class of bench stable compounds with versatile reactivity, and have recently found various applications in bioconjugation [35][36][37] and material science [38][39][40][41][42] due to their ability to undergo rapid ligations 43,44 with O-substituted hydroxylamines or N-chloro amines under mild and dilute conditions to form amides. The union of O-unsubstituted hydroxylamines and KATs, however, results in a nitrone, 45 which upon further activation can rearrangement to an amide.…”

Dynamic Amide Formation by Reversible Nitrone Exchange of Potassium Acyltrifluoroborates (KATs) and Hydroxylamines in Aqueous Conditions

“…Potassium Acyltrifluoroborates (KATs) are a class of bench stable compounds with versatile reactivity, and have recently found various applications in bioconjugation [35][36][37] and material science [38][39][40][41][42] due to their ability to undergo rapid ligations 43,44 with O-substituted hydroxylamines or N-chloro amines under mild and dilute conditions to form amides. The union of O-unsubstituted hydroxylamines and KATs, however, results in a nitrone, 45 which upon further activation can rearrangement to an amide.…”