Dibenzoyldiethylgermane as a visible light photo-reducing agent for CuAAC click reactions

Abstract

A highly active, versatile and visible light-responsive system for CuAAC click reaction using the dibenzoyldiethylgermane photoinitiator with Cu(ii) has been developed.

Post modification of acetylene functional poly(oxindole biphenylylene) by photoinduced CuAAC

“…However, the steric hindrance and molecular weight would still be effective. The solubility of the unreacted PEG segments provides possibility for easy separation and pure graft copolymers are obtained.In this connection, it should be pointed out that the germyl radicals formed from the photolysis of DBDEG in the visible range readily reduces Cu(II) ions to Cu(I) species to trigger successful click reaction [12]. Photo-induced CuAAC reaction of POXI-alkyne with PEG-N 3 .Spectral, molecular weight and thermogravimetric investigations clearly confirm the success of the photo-induced click reaction.…”

“…CuAAC click reactions can be triggered by photochemical means and successfully used for the preparation of complex and functional macromolecular structures and, networks [12][13][14][15][16][17][18][19][20][21][22].…”

Photomediated controlled radical polymerization

“…[51] Considering their role in photoinduced click reactions and photodecomposition pathway, acylgermane photoinitiators were also expected to activate ATRP within the visible range. [64] In another approach, the use of camphorquinone and benzhydrol as photosensitive compounds was investigated for visible light-induced ATRP. [54] In this system, the camphorquinone absorbed visible light and abstracted a hydrogen from benzhydrol to form two ketyl radicals, which were inactive toward the monomer, but were able to reduce Cu(II) to Cu(I) species.…”

Progress on Catalytic Systems Used in Click Polymerization

“…With 56 as photoinitiator, diyne 53 and diazides 54 and 55 were conducted photoinduced polymerizations under 400–500 nm light irradiation at room temperature in the presence of CuCl 2 and N,N,N′,N″,N″ ‐pentamethyldiethylenetriamine ( Scheme ). PTAs 57 and 58 with high molecular weights ( M n up to 107 000) and relative narrow polydispersities were produced in excellent yields (up to 97%) . The use of visible light makes this protocol easy to be implemented in the biological and materials sciences.…”