Article
Polymer Science
Paulina Bednarczyk, Alicja Balcerak-Wozniak, Janina Kabatc-Borcz, Zbigniew Czech
Summary: This study investigates novel two-component photoinitiating systems for the radical polymerization of (meth)acrylate-based compositions. The proposed systems consist of a squaraine dye as a photosensitizer and various onium salts as co-initiators. The newly synthesized squaraines, SQN1 and SQN2, were used in combination with commercially available co-initiators I1 and NO, as well as the newly synthesized NO1. The new photoinitiators demonstrate high activity for the polymerization of (meth)acrylates activated by UV-Vis light. The squaraine derivatives effectively initiate the radical polymerization of methacrylate and acrylate monomers, with conversion rates ranging from 40% to 100% for methacrylates and 30% to 100% for acrylates.
Article
Chemistry, Organic
Mohamed Elsherbini, Wesley J. Moran
Summary: Cyclic and acyclic diaryliodonium salts were synthesized efficiently without the need for chemical oxidants or generation of chemical waste, with yields ranging from very good to excellent. When scaled-up to 10 mmol, over four grams of product with purity above 95% were obtained in less than three hours, and the solvent mixture could be recycled multiple times with minimal reduction in yield.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Review
Chemistry, Organic
Eiji Tayama
Summary: The Sommelet-Hauser rearrangement of X-benzylic onium ylides is an important transformation in organic synthesis. Recent studies in the past 15 years have greatly expanded the scope and synthetic applications of this reaction.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Multidisciplinary
Shubhendu S. Karandikar, Avik Bhattacharjee, Bryan E. Metze, Nicole Javaly, Edward J. Valente, Theresa M. McCormick, David R. Stuart
Summary: Diarylhalonium compounds play important roles as reagents and catalysts in organic synthesis, with the key reactivity of the three center, four electron bond requiring refinement for broader applicability. The combination of Density Functional Theory, Natural Bond Orbital Theory, and X-ray structure data can provide insights into the bonding and structure of these compounds.
Article
Polymer Science
Filip Petko, Andrzej Swiezy, Magdalena Jankowska, Pawel Stalmach, Joanna Ortyl
Summary: In this article, a new group of cationic photoinitiators is introduced and their photophysical properties and photoinitiating activity are analyzed with respect to the arrangement of electron-donating substituents in the coumarin chromophore. The authors observed two patterns of D-pi-A structure in the five new coumarin-based iodonium salts, which differ in the strength of the push-pull effect that determines their properties. These photoinitiators show excellent activity at 365 nm, 405 nm, and 415 nm and exhibit increased activity at elevated temperatures due to thermal reactions with monomers. This photo-thermal initiating activity makes them excellent photoinitiators for nanocomposite DLP 3D-VAT printing, overcoming scattering and shadowing problems.
Article
Chemistry, Multidisciplinary
Wei W. Chen, Margalida Artigues, Merce Font-Bardia, Ana B. Cuenca, Alexandr Shafir
Summary: In this study, novel design principles for the synthesis of cyclic compounds with two hypervalent halogens are presented. The smallest bis-phenylene derivative was prepared through oxidative dimerization of a precursor, and cycles containing two different halogen atoms were formed for the first time. The structures of these bis-halogen rings were analyzed using X-ray analysis. Furthermore, the interaction of the phenylene- and naphthalene-based bis-iodine(III) dications with a new family of rigid bidentate bis-pyridine ligands was explored.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Masaki Fujie, Kyohei Mizufune, Yoshihiro Nishimoto, Makoto Yasuda
Summary: A method for 1-fluoro-1-sulfonyloxylation of styrenes using Bu4NBF4, sulfonic acids, and hypervalent iodine ArI(OAc)(2) is reported. Regression analysis of substituents on ArI(OAc)(2) revealed that their electron-withdrawing ability and steric factor influence the 1,1-heterodifunctionalization. o-{2,4-(CF3)(2)C6H3}- and p-NO2-substituted ArI(OAc)(2) were designed by regression analysis to achieve high selectivity.
Article
Chemistry, Organic
Masaki Fujie, Kyohei Mizufune, Yoshihiro Nishimoto, Makoto Yasuda
Summary: In this study, the 1-fluoro-1-sulfonyloxylation of styrenes using a hypervalent iodine ArI(OAc)2 was reported. Regression analysis showed that the electron-withdrawing ability and steric factor of substituents on ArI(OAc)2 influenced the 1,1-heterodifunctionalization. Designed ArI(OAc)2 derivatives with o-{2,4-(CF3)2C6H3}- and p-NO2-substituents achieved high selectivity.
Article
Chemistry, Organic
Aleksandra Nilova, Bryan Metze, David R. Stuart
Summary: Controlling reaction pathways selectively leads to a broad scope of arenes and arynophiles, offering efficient access to diverse arene chemical space and biologically active compounds with high yields.
Article
Polymer Science
Yang Li, Usman Shaukat, Sandra Schlogl, Tanlong Xue, Jingfang Li, Jun Nie, Xiaoqun Zhu
Summary: Driven by the demand for low cost and environmentally friendly curing processes, the research on synthesis of visible light absorbing photoinitiators has been significant in the field of photo-polymerization. In this study, a novel synthesis route is introduced to obtain a bifunctional pyrrole-carbazole-based photoinitiator (ECMO), which can initiate free radical polymerization upon visible light exposure. ECMO also acts as a sensitizer for triar-ysulfonium salts, extending their absorption window into the visible light region and showing superior curing performance in cationic polymerization.
EUROPEAN POLYMER JOURNAL
(2023)
Review
Polymer Science
Frederic Dumur
Summary: Iodonium salts, a type of cationic photoinitiators, have a long history of use in the polymerization of epoxides or vinyl ethers. However, their UV-centered absorption restricts their use to the visible range through a photosensitization process. To simplify the composition of photopolymerizable resins, various dyes have been covalently linked to iodonium salts, resulting in monocomponent photoinitiating systems. This review provides an overview of the different dyes connected to iodonium salts.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Avery J. To, Graham K. Murphy
Summary: In this study, it was discovered that cyclic diaryliodonium salts can act as effective Lewis-acidic halogen-bond donor catalysts in the Nazarov cyclization reaction.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Prahallad Meher, Satya Prakash Panda, Sanat Kumar Mahapatra, Karan Ramdas Thombare, Lisa Roy, Sandip Murarka
Summary: We report a photoredox system that can form a self-assembled complex and activate diaryliodonium reagents for arylation of heterocycles under mild conditions.
Article
Multidisciplinary Sciences
Owen Smith, Mihai V. Popescu, Madeleine J. Hindson, Robert S. Paton, Jonathan W. Burton, Martin D. Smith
Summary: This paper reports the design, synthesis and characterization of a helically chiral triaryloxonium ion that functions as a determinant of configuration. It is the only example of a chiral non-racemic and configurationally stable molecule in which the oxygen atom is the sole stereogenic centre.
Article
Chemistry, Organic
Lukas Janecky, Athanasios Markos, Blanka Klepetar, Petr Beier
Summary: 4-Aryl-5-allyl-N-fluoroalkyl-1,2,3-triazoles were synthesized through a three-component reaction of fluoroalkyl azides, copper acetylides, and allyl halides. These compounds underwent aluminum halide-mediated transformation to N-(4-halo-2-aryl-cyclopentenyl) imidoyl halides by cyclization of vinyl cation intermediates, followed by halide capture. The cyclic products could be further utilized for the synthesis of N-alkenyl amides, amidines, isoquinolines, and tetrazoles, or for the subsequent modification of the cyclopentene ring.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
