40630-86-2

Usage

Uses

Used in Chemical Synthesis:
Propargyl α-bromoisobutyrate is used as an ATRP initiator for the synthesis of polymers with controlled molecular weights and architectures. Its acetylene functionality allows for Cu-mediated ligation, which is a powerful tool in the development of new materials and products.
Used in Pharmaceutical Industry:
In the pharmaceutical industry, Propargyl α-bromoisobutyrate is used as a key intermediate in the synthesis of various drugs and drug candidates. Its unique chemical properties enable the development of novel therapeutic agents with improved efficacy and selectivity.
Used in Material Science:
Propargyl α-bromoisobutyrate is employed in the field of material science as a building block for the creation of advanced materials with specific properties. Its ability to undergo "click" chemistry allows for the design and synthesis of complex structures with tailored characteristics for various applications.
Used in Research and Development:
In research and development, Propargyl α-bromoisobutyrate serves as a valuable tool for exploring new chemical reactions and mechanisms. Its unique reactivity and functional group compatibility make it an attractive candidate for studying new synthetic pathways and developing innovative methodologies.

Upstream product

• 20769-85-1 2-bromoisobutyric acid bromide 
• 107-19-7 propargyl alcohol 
• 2052-01-9 2-bromo-2-methylpropionic acid 

Downstream Products

• 13861-22-8 prop-2-yn-1-yl methacrylate 

Relevant academic research and scientific papers

Synthesis of poly(2-hydroxyethyl methacrylate) end-capped with asymmetric functional groups via atom transfer radical polymerization

Poly(2-hydroxyethyl methacrylate) (PHEMA) end-capped with living chloride and alkyne groups was synthesized via ATRP of HEMA using CuCl/CuCl 2/2,2′-bipyridine as a catalyst in a solvent mixture of methanol and 2-butanone. The effects of parameters including the initiator, solvent, temperature and initial monomer to initiator ratios on polymerization were studied in terms of polymerization kinetics, the degree of polymerization (DP) and molar mass dispersity (D) of the resulting PHEMA polymer. ATRP of HEMA using propargyl 2-bromoisobutyrate (PBiB) as an initiator was poorly controlled, but those using 3-(trimethylsilyl)propargyl 2-bromoisobutyrate (TMSPBiB) and 3-(triisopropysilyl)propargyl 2-bromoisobutyrate (TiPSPBiB) as initiators were well-controlled. Moreover, the apparent propagation rate constant for ATRP of HEMA using the TMSPBiB initiator was higher than that using the TiPSPBiB initiator. The solvent mixture of methanol-2-butanone at different compositions greatly affected the polymerization controllability. A high molecular weight PHEMA sample with a DP of 1000 and a D of 1.34 was obtained under appropriate conditions. The poly(2-hydroxyethyl methacrylate)-block-poly(butyl acrylate) (PHEMA-b-PBA) diblock copolymer was prepared through ATRP of BA using (CH 3)3Si-CC-PHEMA-Cl as a macroinitiator. The methoxyl polyethylene glycol-block-poly(2-hydroxyethyl methacrylate) (MPEG-b-PHEMA) diblock copolymer was prepared by click reaction between MPEG-N3 and HCC-PHEMA-Cl. These two reactions demonstrated the reactivity of the asymmetric functional groups end-capping the PHEMA, and further provided modular examples for the synthesis of a novel well-defined (co)polymer with complex architectures. This journal is the Partner Organisations 2014.

β-Cyclodextrin-appended giant amphiphile: Aggregation to vesicle polymersomes and immobilisation of enzymes

A giant amphiphile consisting of polystyrene end-capped with permethylated ss-cyclodextrin was synthesised and found to form vesicular structures when injected as a solution in THF into water. The ability of the cyclodextrins on the surface of the polymersomes to form inclusion complexes with hydrophobic compounds was tested by carrying out a competition experiment with a fluorescent probe sensitive to the polarity of the surrounding medium. It was found that 1-adamantol can displace the fluorescent probe from the cavities of the cyclodextrin moieties of the polymersomes. The recognition of molecules by cell membranes in nature is often based on interactions with specific membrane receptors. To mimic this behaviour, the enzyme horseradish peroxidase was modified with adamantane groups through a poly(ethylene glycol) spacer and its interaction with the polymersomes was investigated. It was established that the presence of adamantane moieties on each enzyme allowed a host-guest interaction with the multifunctional surface of the polymersomes.

Synthesis and properties of comb polymers with semirigid mesogen-jacketed polymers as side chains

A series of novel comb polymers, poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl] styrene}-g-polystyrene (PMPCS-g-PS), with mesogen-jacketed rigid side chains were synthesized by the "grafting onto" method from α-yne-terminated PMPCS (side chain) and poly(vinyl

Thermoresponsive Semiconducting Polymer Nanoparticles for Contrast-Enhanced Photoacoustic Imaging

Photoacoustic (PA) agents with biomarker-activated signals are developed to enhance the signal-to-background ratios (SBRs) for in vivo imaging; however, their SBRs still heavily rely on the concentration difference of biomarkers between diseased and normal tissues. By contrast, external stimuli can provide a remote way to noninvasively control the signal generation from the PA agents and in turn enhance SBR, which are less exploited. This study reports the development of thermoresponsive semiconducting polymer brush with poly(N,N-dimethylacrylamide)-r-(hydroxypropyl acrylate) (PDMA-r-HPA) grafts for contrast-enhanced in vivo imaging. Such a polymer is amphiphilic and can self-assemble into the nanoparticle (termed as SPNph1) in an aqueous medium, and has lower critical solution temperatures (LCSTs) at 48 °C. Thus, SPNph1 not only has higher photothermal conversion efficiency than the control polymer without PDMA-r-HPA grafts, but also can undergo phase separation to form large nanoparticles, leading to enhanced PA signals above LCST. The thermoresponsive PA property of SPNph1 enables in situ remote manipulation of PA signals by photoirradiation to further enhance the tumor SBR. Thus, this study introduces a new generation of organic PA agents with thermoresponsive signal for high-contrast in vivo imaging.

Synthesis of tadpole-shaped POSS-containing hybrid polymers via "click chemistry"

Copper-catalyzed alkyne-azide "click chemistry" is applied in the preparation of tadpole-shaped ("monochelic") POSS-end functional hybrid polymers by combining with ATRP and RAFT polymerization. Alkyne-functionalized ATRP initiator and RAFT agent were respectively synthesized and applied in the preparation of alkyne-terminal poly(methyl methacrylate) and polystyrene. The tadpole-shaped POSS-containing hybrid polymers are easily obtained by the click reaction with an azido-functional POSS molecule. This presents a novel and effective method to prepare POSS-containing hybrid polymers.

Step-growth "click" coupling of telechelic polymers prepared by atom transfer radical polymerization

The synthesis of homo- or heterotelechelic polymers and their efficient step-growth click coupling in the presence of CuBr, prepared by atom transfer radical polymerization (ATRP) was investigated. It was found that ATRP is an attractive technique for the synthesis of well-defined end-functionalized polymers. Homo- and heterotelechelic polySty oligomer prepared by the ATRP method were coupled via step-growth click coupling to yield polySty containing 1,2,3-triazole linkages. The SEC and H NMR spectroscopy results indicated the possibility of an intramolecular click reaction to yield cyclic polymers in DMF.

Solvent replacement to thermo-responsive nanoparticles from long-subchain hyperbranched PSt grafted with PNIPAM for encapsulation

Long-subchain hyperbranched polystyrene (lsc-hp PSt) with uniform subchain length was obtained through copper-catalyzed azide-alkyne cycloaddition click chemistry from seesaw macromonomer of PSt having one alkynyl group anchored at the chain centre and two azido group attached to both chain ends [alkynyl-(PSt-N3)2]. After precipitation fraction, different portions of lsc-hp PSt having narrow overall molecular weight distribution were obtained for further grafting with alkynyl-capped poly(N-isopropylacrylamide) (alkynyl-PNIPAM), which was obtained via single-electron transfer living radical polymerization of NIPAM with propargyl 2-bromoisobutyrate as the initiator and grafted onto the peripheral azido groups of lsc-hp PSt via click chemistry. Thus, amphiphilic lsc-hp PSt grafted with PNIPAM chains (lsc-hp PSt-g-PNIPAM) was obtained and would have star-like conformation in tetrahydrofuran (THF). By replacing THF with water, lsc-hp PSt-g-PNIPAM was dissolved at molecular level in aqueous solution due to the hydrophilicity of PNIPAM and exhibited thermal induced shrinkage of PNIPAM arms. The water-insoluble lsc-hp PSt would collapse densely and could be served as a reservoir to absorb hydrophobic chemicals in aqueous solution. The influence of overall molecular weight of lsc-hp PSt on the absorption of pyrene was studied.

Self-assembly behavior of amphiphilic linear-block-dendritic copolymers with long subchains: Dependences on dendron generation and mixing dynamics

Block copolymers composed of acrylic acid and methyl methacrylate with three topologies of double linear blocks, poly(acrylic acid) (PAA) linear block/poly(methyl methacrylate) (PMMA) G1-dendron and PAA linear block/PMMA G2-dendron have been prepared by the combination of atom transfer radical polymerization and azide–alkyne click reaction. Proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and gel permeation chromatography have been adopted thoroughly to identify the chemical structure of those block copolymers with expected topologies. The self-assembly of those block copolymers in the selective solvent has been performed through two mixing routes of gentle and abrupt variation in solvent selectivity, and the morphology of the obtained self-assemblies/aggregates was observed by transmission electron microscopy. Because the abrupt variation route altered sharply the solvent quality during the mixing, the intermolecular association of polymer chains resulted in the smaller self-assemblies but the further growth of smaller self-assemblies was not observed. On the contrary, the gentle variation route changed gradually the solvent quality during the mixing, favoring not only the intermolecular association but also the further growth of self-assemblies to result in larger aggregates. The final morphology of those assemblies/aggregates also exhibited the dependence of PMMA dendron generation.

Synthesis and hierarchical self-assembly of rod-rod block copolymers via click chemistry between mesogen-jacketed liquid crystalline polymers and helical polypeptides

A series of novel rod-rod diblock copolymers containing poly{2,5-bis[(4-methoxyphenyl)-oxycarbonyl]styrene} (PMPCS) and poly(γ-benzyl-L-glutamate) (PBLG) were synthesized by click chemistry from alkyne-and azide-functionalized homopolymers. The α-alkyne PMPCS homopolymers were synthesized by copper-mediated atom transfer radical polymerization with a bromine-containing α-alkyne bifunctional initiator, and α-azido PBLG homopolymers were synthesized by ring-opening polymerization of γ-benzyl-L-glutamate N-carboxyanhydride with an amino-containing α-azide initiator. The molecular structures of the rod-rod block copolymers were confirmed by 1H NMR spectroscopy, Fourier transform infrared spectroscopy, and gel permeation chromatography analysis. The self-assembling behavior of the rod-rod block copolymers in bulk was investigated using differential scanning calorimetry, polarized light microscopy, wide-angle X-ray diffraction, and transmission electron microscopy techniques. A lamellar structure was observed with fPBLG of ～0.50, in which PMPCS was in a columnar nematic phase and PBLG assignedto a hexagonally packed-cylinder structure (ΦH). Accordingto the TEM micrographs and simulated lengths of the copolymers, a stacked bilayer structure in a hexagon in lamella morphology for the selfassembly of the rod-rod block copolymers was proposed. Finally, by increasing fPBLG to ～0.69, a microphase-separated hexagon in cylinder morphology was found, in which PMPCS formed the core of the cylinders surrounded by PBLG in ΦH phase and both rods were in an interdigitated packing.

Cyclic azobenzene-containing side-chain liquid crystalline polymers: Synthesis and topological effect on mesophase transition, order, and photoinduced birefringence

A cyclic side-chain liquid crystalline polymer (SCLCP) bearing azobenzene mesogens, namely, poly{6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate} (PAzoMA), was successfully synthesized by using "click" cyclization of the linear polymer precursor with alkyne and azide end groups. Samples of cyclic-PAzoMA of various molecular weights were prepared, characterized, and studied in comparison with their linear counterparts. The results show that the topological constraint arising from the tortuosity of the ring structure and the absence of chain ends in cyclic-SCLCPs affects profoundly the liquid crystalline (LC) phase transitions (temperature, enthalpy, and entropy) of mesogenic side groups and that this topological effect is more prominent for smaller SCLCP rings. Moreover, the photoinduced anisotropy in films as a result of the trans-cis photoisomerization of azobenzene mesogens was investigated, and cyclicPAzoMA was found to behave differently from linear-PAzoMA. On the one hand, the cyclic polymer exhibits a nonmonotonic rise and erasure of birefringence upon linearly and circularly polarized excitation (488 nm), respectively, in contrast with the linear polymer displaying monotonic changes. On the other hand, unlike the linear polymer, the photoinduced orientation of azobenzene mesogens in cyclic-PAzoMA cannot be enhanced upon annealing in the nematic phase. All these manifestations of the topological constraint suggest that cyclization offers a new way to change the coupling between mesogenic side groups and chain backbone of SCLCPs, and their interplay under the additional topological effect may generate new behaviors that are of interest to be explored.