Photoactivated catalysts for the hydrosilylation of alkenes with silanes offer temporal control in manufacturing processes that require silicone curing. We report the development of a range of air-stable Pt(II) (salicylaldimine)(phenylpyridyl), [Pt(sal)(ppy)], complexes as photoinitiated hydrosilylation catalysts. Some of these catalysts show appreciable latency in thermal catalysis and can also be rapidly (10 s) activated by a LED UV-light source (365 nm), to give systems that selectively couple trimethylvinylsilane and hexamethylsiloxymethylsilane to give the linear hydrosilylation product. Although an undetectable (by NMR spectroscopy) amount of precatalyst is converted to the active form under UV-irradiation in the timescale required to initiate hydrosilylation, clean and reliable kinetics can be measured for these systems that allow for a detailed mechanism to be developed for Pt(sal)(ppy)-based photoactivated hydrosilylation. The suggested mechanism is shown to have close parallels with, but also subtle differences from, those previously proposed for thermally-activated Karstedt-type Pt(0) systems.
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http://dx.doi.org/10.1021/acscatal.4c01353 | DOI Listing |
Chemistry
December 2024
Department of Pharmacy, University of Naples Federico II, via D. Montesano 49, 80131, Naples, Italy.
Porous silicon is one of the most explored nanostructured materials in various biomedical applications owing to its remarkable properties. However, its inherent chemical instability mandates a robust surface modification procedure, and proper surface bioengineering is essential to ensure its effectiveness in the biomedical field. In this study, we introduce a one-pot functionalization strategy that simultaneously stabilizes porous silicon nanoparticles and decorates their surface with carbohydrates through hydrosilylation chemistry, combining mild temperatures and a Lewis acid catalyst.
View Article and Find Full Text PDFInorg Chem
December 2024
Department of Chemistry, Indian Institute of Science Education and Research, Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008 Maharashtra, India.
The 5,6-Bis(diisopropylphosphino)acenaphthene -stabilized Sb(I) cationic compound [LSb][OTf] (OTf = CFSO) possessing two lone pairs of electrons on the Sb(I) center showed nucleophilic behavior toward methyl trifluoromethanesulfonate forming the oxidized product [LSbMe][OTf] (OTf = CFSO). Reaction of compound with Lewis acids such as GaCl and AlBr led to changes in the counteranions only giving products [LSb][GaCl] and [LSb][SbBr] , respectively. A metathesis reaction was observed when compound was reacted with PI.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry and Fujian Provincial Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, P. R. China.
Reported herein is a convenient and efficient method for one-pot, catalytic reductive amination, as well as the first multi-component tandem reductive amination-functionalization of bench-stable and readily available common carboxylic esters. This method is based on the cationic [Ir(COD)]BArF-catalyzed chemoselective hydrosilylation of esters, followed by one-pot acid-mediated amination and nucleophilic addition. The reaction was conducted under mild conditions at a very low catalyst loading (0.
View Article and Find Full Text PDFInorg Chem
December 2024
College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P. R. China.
Macromolecules
November 2024
Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States.
Silicone bottlebrush copolymers and networks derived from cyclic carbosiloxanes are reported and shown to have enhanced properties and recyclability compared with traditional dimethylsiloxane-based materials. The preparation of these materials is enabled by the synthesis of well-defined heterotelechelic macromonomers with Si-H and norbornene chain ends via anionic ring-opening polymerization of the hybrid carbosiloxane monomer 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane. These novel heterotelechelic α-Si-H/ω-norbornene macromonomers undergo efficient ring-opening metathesis copolymerization to yield functional bottlebrush polymers with accurate control over molecular weight and functional-group density.
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