Automated Synthesis of Well‐Defined Polymers and Biohybrids by Atom Transfer Radical Polymerization Using a DNA Synthesizer

Abstract

A DNA synthesizer was successfully employed for preparation of well-defined polymers by atom-transfer radical polymerization (ATRP), in a technique termed AutoATRP. This method provides well-defined homopolymers, diblock copolymers, and biohybrids under automated photomediated ATRP conditions. PhotoATRP was selected over other ATRP methods because of mild reaction conditions, ambient temperature, tolerance to oxygen, and no need to introduce reducing agents or radical initiators. Both acrylate and methacrylate monomers were successfully polymerized with excellent control in the DNA synthesizer. Diblock copolymers were synthesized with different targeted degrees of polymerization and with high retention of chain-end functionality. Both hydrophobic and hydrophilic monomers were grafted from DNA. The DNA-polymer hybrids were characterized by SEC and DLS. The AutoATRP method provides an efficient route to prepare a range of different polymeric materials, especially polymer-biohybrids.

An Oxygen‐Tolerant PET‐RAFT Polymerization for Screening Structure–Activity Relationships

“…Many studies have shown that the multivalent presentation of ligands to soluble proteins and cell receptors is highly dependent on ligand density,spacing, and orientation. [6][7][8][9][10][11][12] There has therefore been growing interest in methods that will enable the high throughput synthesis and screening of well-defined polymers.Early works showed the possibility of using automatic synthesisers to conduct conventional controlled radical polymerisations (CRPs) in inert atmospheres, [13][14][15][16][17] but the recent development of various oxygen tolerant CRP mechanisms including singlet oxygen trapping, [18][19][20][21][22][23] enzyme degassing, [24][25][26][27][28][29] among others, [14,[30][31][32][33] have now been applied to the synthesis of polymer libraries in low volumes and open to the atmosphere. [34][35][36][37][38][39] These techniques have been used to prepare polymers with complex architectures such as arm first stars, [36,37] and block copolymers, [39] and have been applied to the investigation of polymerisationinduced self-assembly (PISA) systems.…”

Oxygen‐Tolerant Photochemically Induced Atom Transfer Radical Polymerization of the Renewable Monomer Tulipalin A

“…Similarly, Matyjaszewski's group demonstrated that an optical fibre UV source can be used for the oxygen-tolerant photoATRP of (meth)acrylates. [24] Poly et al demonstrated that complex of CuBr 2 with 1,10-phenanthroline as ligand can be employed in the mediation of the photoATRP of MMA in the presence of oxygen under high-intensity blue LED light. [25] Although various polymerization techniques have been used for the polymerization of MBL, there was no report on conducting a reversible deactivation radical polymerization of MBL using low concentration of catalyst in the presence of oxygen.…”

Oxygen‐Initiated and Regulated Controlled Radical Polymerization under Ambient Conditions

“…[2,7,17] Theinitial homolytic substitution (S H 2) between triethylborane and oxygen molecule provided ethyl radical (EtC)and boryl peroxyl radical (BOOC). Thefirst oxidized boron adduct could be cleaved and rearranged to EtB(OEt) 2 ,a nd finally formed B(OEt) 3 .T hree key boron intermediates were all detected by 11 BNMR spectroscopy (Supporting Information, Figure S10). Thee thylperoxy radical was involved in another S H 2 reaction with triethylborane to form active ethyl radical and corresponding oxidized boron product Et 2 B(OOEt).…”

“…The freeze-pump-thaw technique and deoxygenation with inert gas are widely used but time-consuming methods to remove oxygen. Several methods with some degree of oxygen tolerance were developed via consuming oxygen by excess radicals or converting oxygen to non-initiating species, including photoinduced atom-transfer radical polymerization (photoATRP), [3] photoinduced electron/energy-transferreversible addition-fragmentation chain-transfer (PET-RAFT). [4] Glucose oxidase (GOx) was capable of converting oxygen with d-glucose into hydrogen peroxide;t herefore,i tw as elegantly adopted as oxygen scavenger in RAFT [5] and ATRP under ambient atmosphere.…”

“…Thee thylperoxy radical was involved in another S H 2 reaction with triethylborane to form active ethyl radical and corresponding oxidized boron product Et 2 B(OOEt). Thefirst oxidized boron adduct could be cleaved and rearranged to EtB(OEt) 2 ,a nd finally formed B(OEt) 3 .T hree key boron intermediates were all detected by 11 BNMR spectroscopy (Supporting Information, Figure S10).…”