Ultrafast Click Conjugation of Macromolecular Building Blocks at Ambient Temperature

Abstract

Block copolymers in seconds: Catalyst-free, ambient-temperature click conjugation of individual polymer strands becomes possible using novel ATRP-derived cyclopentadienyl-capped polymers in an extremely rapid hetero-Diels-Alder cycloaddition with macromolecules equipped with electron-deficient dithioester end groups prepared by the RAFT process.

“Click” reactions in polysaccharide modification

“…This reaction type, termed "hetero Diels-Alder" (hDA, Scheme 2b), has also proven to be a fast and efficient click reaction. In 2009 [114] the Barner-Kowollik group demonstrated an efficient, extremely rapid, room temperature conjugation strategy via hDA that utilized a cyclopentadienyl group (Cp) as the diene and thiocarbonylthio compounds as dienophiles. Later, they reported the first applications of hDA to modify cellulose surfaces.…”

“…nitrosocarbonyl compounds [113], and thiocarbonyl thio compounds [114]). This reaction type, termed "hetero Diels-Alder" (hDA, Scheme 2b), has also proven to be a fast and efficient click reaction.…”

Poly(bromoethyl acrylate): A Reactive Precursor for the Synthesis of Functional RAFT Materials

“…[6][7][8] In light of this, post-modification of a reactive polymer precursor provides an attractive approach to overcoming this limitation, enabling synthesis of diversely functional materials, without subjecting them to detrimental polymerization conditions. [9][10][11][12][13] A variety of post-polymerization methods have previously been explored, [6][7][8][9] including copper-catalysed azide/alkyne click (CuAAC), [14][15][16] Diels-Alder cycloadditions [17][18][19][20] and active ester couplings. 10,[21][22][23] These methods enable the introduction of complex functional groups targeting applications ranging from drug delivery to organic electronics.…”

Reversible oligomerization of 3-aryl-2-cyanothioacrylamides via [2s + 4s] cycloaddition to substituted 3,4-dihydro-2H-thiopyrans

“…For example, the highly electron-deficient dithioesters that are present as end-groups of polymers obtained via the reversible addition-fragmentation chain transfer polymerization using specially designed chain transfer agents have been utilized for HDA reactions by Barner-Kowollik and coworkers. [8][9][10][11][12][13][14][15][16][17][18] Networks based on tetrafunctional dithioesters and bifunctional cyclopentadiene showed self-healing behavior. [19] Moreover, Lehn and coworkers investigated highly reversible and dynamic DA systems.…”