A novel copper catalyst containing a hydroxyl functional group: a facile strategy to prepare block copolymers of vinyl monomer and ε-caprolactone via tandem reverse ATRP and ROP

2017 ◽  
Vol 8 (32) ◽  
pp. 4752-4760 ◽  
Author(s):  
Xiao-hui Liu ◽  
Qiu-yan Zhang ◽  
Wen-li Di ◽  
Yan-guang Zhang ◽  
Chen Ding

A facile hydroxyl-functionalized catalyst was first accessed to prepare block copolymers of vinyl and cyclic ester monomers via tandem reverse ATRP/ROP.

1968 ◽  
Vol 6 (4) ◽  
pp. 979-992 ◽  
Author(s):  
Yuji Minoura ◽  
Minoru Shundo ◽  
Yasushi Enomoto

2011 ◽  
Vol 284-286 ◽  
pp. 769-772
Author(s):  
Qian Qian You ◽  
Pu Yu Zhang

The block copolymer of PSt-b-POEOMA with the end of -COOH functional group has been synthesized by reversible addition fragmentation chain-transfer (RAFT) using S,S′-Bis(α,α′-dimethyl-α′′-acetic acid)-trithiocarbonate (BDATC) as a chain transfer agent. The architectures of the copolymers were confirmed by FT-IR and 1HNMR spectra. GPC analysis was used to estimate the molecular weight and the molecular weight distribution of the copolymers. Meanwhile, The nanostructures of the block copolymers PSt-b-POEOMA micelles formed in aqueous solution were observed by transmission electron microscopy (TEM) and dynamic light scattering (DLS).


2013 ◽  
Vol 228 ◽  
pp. S24-S27 ◽  
Author(s):  
Dong-Jin Wu ◽  
Zhi-Xu Liu ◽  
Chun-Zheng Gao ◽  
Xing-Can Shen ◽  
Xiu-Mei Wang ◽  
...  

2021 ◽  
Author(s):  
Vaishnavi Nair ◽  
Volga Kojasoy ◽  
Croix Laconsay ◽  
Dean Tantillo ◽  
Uttam Tambar

We have developed catalyst-controlled regiodivergent rearrangements of onium-ylides derived from indole substrates. Oxonium ylides formed <i>in situ</i> from substituted indoles selectively undergo [2,3]- and [1,2]-rearrangements in the presence of a rhodium and copper catalyst, respectively. The combined experimental and density functional theory (DFT) computational studies indicate divergent mechanistic pathways involving a metal-free ylide in the rhodium catalyzed reaction favoring [2,3]-rearrangement, and a metal-coordinated ion-pair in the copper catalyzed [1,2]-rearrangement that recombines in the solvent-cage. The application<br>of our methodology was demonstrated in the first total synthesis of the indole alkaloid (±)-sorazolon B, which enabled the stereochemical reassignment of the natural product. Further functional group transformations of the rearrangement products to generate valuable synthetic intermediates were also demonstrated.


2019 ◽  
Vol 948 ◽  
pp. 192-197
Author(s):  
Kartika Sari ◽  
Edi Suharyadi ◽  
Roto Roto ◽  
Kamsul Abraha

Nano-sized chitosan has been prepared by ball mill (High Energy Milling) with 1500 rpm to determine itsgrainz size and functional group. A nanopowder sample was prepared in the various milling time of the precusor. The milling time were 60, 120, 180, 240, 300 and 360 minutes. The Scanning Electron Microscopy (SEM)images indicated that the microstructures and grain size of as-prepared chitosan changed by increasing the milling time. The average of grain size is 15,1 nm. The Fourier Transform Infra-Red (FTIR) spectra showedthat the -OH bond shifted after milling process. The new C=O roups formedduring the milling process, because of the ordered microstructures in the nano-sized chitosan granules weredestroyed after ball millingThe surface area of the nano-sized chitosan was high, the particles tend to agglomerate since the ionic electrostatic could not prevent to form the agglomeration. The ball milling treatment was an effective method to reduce the grain size of chitosan, and functional groups will not automatically change during the milling process.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tetsuya Okuda ◽  
Katsuya Kato ◽  
Masahiro Kitamura ◽  
Shinjiro Kasahara

AbstractHere, we describe porous zirconia particles (PZPs) optimized for the purification of immunoglobulins. PZPs, with a pore size of approximately 10 nm, were designed to specifically interact with antibodies via surface modification with a phosphate functional group. A simple PZP purification method based on precipitation enabled efficient purification of mouse anti-glycosphingolipid globoside/Gb4Cer monoclonal IgM (κ-light chains) from hybridoma culture supernatants. Over 99% of contaminating proteins were removed by the PZP purification process, and approximately 50% of the IgM was recovered in the purified fraction after eluting the PZP-adsorbed antibodies with 100 mM phosphate buffer. Other IgG3 and IgM monoclonal antibodies that react with Gb4Cer or α2,6-sialyl LacNAc-modified glycoproteins could also be purified using PZPs and elution buffer at concentrations of 100–500 mM. All of the purified antibodies retained their antigen reactivity and specificity, indicating that PZP purification does not affect antibody function. As PZP purification is also suitable for purification of IgM consisting of λ-light chains and IgG derived from other mammalian species, it is expected to be applied to the purification of a variety of antibodies, including anti-glycoconjugate IgMs.


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