RAFT polymerization of N-vinylpyrrolidone mediated by cyanoprop-2-yl-1-dithionaphthalate in the presence of a fluoroalcohol: the possibility of altering monomer properties by hydrogen bonding?

Liu, Qingqing; Wu, Huaqiao; Zhang, Liuqiao; Zhou, Yu; Zhang, Wei; Pan, Xiangqiang; Zhang, Zhengbiao; Zhu, Xiulin

doi:10.1039/c5py02047f

Cited by 19 publications

(11 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Analogous hydrogen bonding has been observed numerous times, for example between HFIP and amino acids. [98][99][100][101] In accordance with this proposal, the MW calculated for mononuclear complexes diffusing alongside one molecule of HFIP (1:1:2•HFIP) lies well within the measured range of diffusion constants.…”

Section: Scheme 5 Proposed Active Species and Resting Statesupporting

confidence: 68%

Mechanism of the Arene-Limited Nondirected C–H Activation of Arenes with Palladium: A Combined Experimental and Theoretical Study

Wedi¹,

Bergander²,

Mück‐Lichtenfeld³

et al. 2019

Preprint

View full text Add to dashboard Cite

Recently, synthetic methods have been discovered which enable the directing group-free C–H activation of arenes with palladium-catalysts and do not require an excess of the arene substrate. By overcoming this long standing challenge, such methods have now become suitable for the functionalization of complex organic molecules. The key to success in several of these transformations has been the use of two complementary ligands, an N-acyl amino acid and an Nheterocycle. Further applications of this design principle will likely require the guidance by a profound mechanistic understanding. This prompted us to engage in a detailed experimental and computational mechanistic study of the dual ligand enabled C–H activation of arenes. Based on comprehensive kinetic experiments, (CID-)MS, (DOSY-)NMR, and DFT calculations we find that a 1:1:1 complex of palladium and the two ligands is indeed the active species that enables a partially rate-limiting concerted C–H activation as part of a Pd<sup>0</sup>/Pd<sup>II</sup>-cycle. Our study highlights the importance of catalyst speciation and allows us to rationalize the role of each ligand as well as the observed regioselectivities. These findings are expected to be highly useful for further method development using this powerful class of catalysts.

show abstract

Section: Scheme 5 Proposed Active Species and Resting Statesupporting

confidence: 68%

Mechanism of the Arene-Limited Nondirected C–H Activation of Arenes with Palladium: A Combined Experimental and Theoretical Study

Wedi¹,

Bergander²,

Mück‐Lichtenfeld³

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…With increasing HFIP/toluene ( v / v ) (from 1/3 through 1/1 to 3/1), the induction periods were significantly reduced ( Figure 1 i–k). These results implied that the HFIP was probably associated with N-PMI via hydrogen bonding, which might alter the reactivity of N-PMI [ 8 , 9 , 10 ]. The hydrogen bonding interaction between HFIP and N-PMI units was explored by adding HFIP portion-wise into the copolymer in toluene.…”

Section: Resultsmentioning

confidence: 99%

“…According to the simulation structure in Figure S3 , the Mulliken charge of pivotal atoms in N-PMI all revealed meaningful changes when N-PMI interacted with HFIP. These results implied that the electron cloud distribution was altered by the introduction of hydrogen bonding [ 8 , 10 ]. To clearly elucidate the role of hydrogen bonding in the polymerization, molecular orbital based on computer simulation was used [ 22 ], simulating the lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO).…”

Section: Resultsmentioning

confidence: 99%

“…Okamoto et al speculated that the interactions between hydrogen bonding donor and hydrogen bonding receptor could form a monomer-activating effect due to the electron induction effects [ 7 ]. Our group reported that HFIP could be applied in controlled radical polymerization of 2-vinylpyridine (2VP) [ 8 ], 4-vinylpyridine (4VP) [ 9 ], and N -vinylpyrrolidone (NVP) [ 10 ] for better molecular weight, tacticity, and sequence control. Through elaborate NMR investigation, the monomer-activating effect was firstly proved by experimental evidence and computer simulation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

RAFT Polymerization of Styrene and Maleimide in the Presence of Fluoroalcohol: Hydrogen Bonding Effects with Classical Alternating Copolymerization as Reference

et al. 2017

Self Cite

View full text Add to dashboard Cite

Abstract:The impacts of hydrogen bonding on polymerization behavior has been of interest for a long time; however, universality and in-depth understanding are still lacking. For the first time, the effect of hydrogen bonding on the classical alternating-type copolymerization of styrene and maleimide was explored. N-phenylmaleimide (N-PMI)/styrene was chosen as a model monomer pair in the presence of hydrogen bonding donor solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), which interacted with N-PMI via hydrogen bonding. Reversible addition-fragmentation chain transfer polymerization (RAFT) technique was used to guarantee the "living" polymerization and thus the homogeneity of chain compositions. In comparison with the polymerization in non-hydrogen bonding donor solvent (toluene), the copolymerization in HFIP exhibited a high rate and a slight deviation from alternating copolymerization tendency. The reactivity ratios of N-PMI and St were revealed to be 0.078 and 0.068, respectively, while the reactivity ratios in toluene were 0.026 and 0.050. These interesting results were reasonably explained by using computer simulations, wherein the steric repulsion and electron induction by the hydrogen bonding between HFIP and N-PMI were revealed. This work first elucidated the hydrogen bonding interaction in the classical alternating-type copolymerization, which will enrich the research on hydrogen bonding-induced polymerizations.

show abstract

“…In 2007, Lu et al reported the application of atom transfer radical polymerization (ATRP) in producing PVP of molecular weight around 8900 with PDI of 1.2–1.38 [ 32 , 33 ]. Advances in the procedures of controlled radical polymerization (CRP)/LRP [ [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] ], ATRPf [ 43 ], and reversible addition-fragmentation transfer radical polymerization (RAFT) [ 44 , 45 ] have created new avenues for better control on the synthesis of PVP and its derivatives.…”

Section: Preparation Methods Of Pvp and Its Derivativesmentioning

confidence: 99%

Pharmaceutical assessment of polyvinylpyrrolidone (PVP): As excipient from conventional to controlled delivery systems with a spotlight on COVID-19 inhibition

Kurakula

Rao

2020

Journal of Drug Delivery Science and Technology

292

172

View full text Add to dashboard Cite

Polyvinylpyrrolidone (PVP) is a water-soluble polymer obtained by polymerization of monomer N -vinylpyrrolidone. PVP is an inert, non-toxic, temperature-resistant, pH-stable, biocompatible, biodegradable polymer that helps to encapsulate and cater both hydrophilic and lipophilic drugs. These advantages enable PVP a versatile excipient in the formulation development of broad conventional to novel controlled delivery systems. PVP has tunable properties and can be used as a brace component for gene delivery, orthopedic implants, and tissue engineering applications. Based on different molecular weights and modified forms, PVP can lead to exceptional beneficial features with varying chemical properties. Graft copolymerization and other techniques assist PVP to conjugate with poorly soluble drugs that can inflate bioavailability and even introduces the desired swelling tract for their control or sustained release. The present review provides chemistry, mechanical, physicochemical properties, evaluation parameters, dewy preparation methods of PVP derivatives intended for designing conventional to controlled systems for drug, gene, and cosmetic delivery. The past and growing interest in PVP establishes it as a promising polymer to enhance the trait and performance of current generation pharmaceutical dosage forms. Furthermore, the scrutiny explores existing patents, marketed products, new and futuristic approaches of PVP that have been identified and scope for future development, characterization, and its use. The exploration spotlights the importance and role of PVP in the design of Povidone-iodine (PVP–I) and clinical trials to assess therapeutic efficacy against the COVID-19 in the current pandemic scenario.

show abstract

RAFT polymerization of N-vinylpyrrolidone mediated by cyanoprop-2-yl-1-dithionaphthalate in the presence of a fluoroalcohol: the possibility of altering monomer properties by hydrogen bonding?

Abstract: This work illustrated the possibility of altering the monomer properties by using the hydrogen bonding interaction.

Cited by 19 publications

References 59 publications

Mechanism of the Arene-Limited Nondirected C–H Activation of Arenes with Palladium: A Combined Experimental and Theoretical Study

Mechanism of the Arene-Limited Nondirected C–H Activation of Arenes with Palladium: A Combined Experimental and Theoretical Study

RAFT Polymerization of Styrene and Maleimide in the Presence of Fluoroalcohol: Hydrogen Bonding Effects with Classical Alternating Copolymerization as Reference

Pharmaceutical assessment of polyvinylpyrrolidone (PVP): As excipient from conventional to controlled delivery systems with a spotlight on COVID-19 inhibition

Contact Info

Product

Resources

About