Here, we introduce a new class of titanocene catalysts for epoxide hydrosilylation that frustrates their hydridicity and thereby emphasizes their electron transfer reactivity. This unique attenuation of hydridicity is accomplished by introducing Lewis acidic silicon centers to the cyclopentadienyl ligands for an intramolecular coordination of the titanium-bound hydride. The superiority of our rationally designed catalysts over classic titanocenes with alkyl-substituted cyclopentadienyl ligands is demonstrated in the dramatically improved regioselectivity of the hydrosilylation of monosubstituted epoxides to primary alcohols.
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http://dx.doi.org/10.1002/chem.202402694 | DOI Listing |
Pharmaceuticals (Basel)
January 2025
Centro de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Background/objectives: Cancer remains one of the major challenges of our century. Organometallic ruthenium complexes are gaining recognition as a highly promising group of compounds in the development of cancer treatments.
Methods: Building on the auspicious results obtained for [Ru(η-CH)(PPh)(bipy)][CFSO] (TM34), our focus has shifted to examining the effects of incorporating bioactive ligands into the TM34 framework, particularly within the cyclopentadienyl ring.
J Am Chem Soc
January 2025
Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, Netherlands.
We present the synthesis, structural analysis, and remarkable reactivity of the first carbon nanohoop that fully incorporates ferrocene in the macrocyclic backbone. The high strain imposed on the ferrocene by the curved nanohoop structure enables unprecedented photochemical reactivity of this otherwise photochemically inert metallocene complex. Visible light activation triggers a ring-opening of the nanohoop structure, fully dissociating the Fe-cyclopentadienyl bonds in the presence of 1,10-phenanthroline.
View Article and Find Full Text PDFOrganometallics
January 2025
Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom.
Cyclopentadienyl anions ([Cp]) are pervasive ligands in coordination chemistry. In contrast, heavy-element derivatives of these ligands, particularly those that feature arsenic, are not as well developed. In this work, a new arsenic-based heterocycle with a structure analogous to [Cp] is presented.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
The enantioselective [3+2] annulation of readily accessible aldimines with alkynes via C-H activation is, in principle, a straightforward and atom-efficient route for synthesizing chiral 1-aminoindenes, which are important components in a wide array of natural products, bioactive molecules, and functional materials. However, such asymmetric transformation has remained undeveloped to date due to the lack of suitable chiral catalysts. Here, we report for the first time the enantioselective [3+2] annulation of aldimines with alkynes via C-H activation using chiral half-sandwich scandium catalysts.
View Article and Find Full Text PDFACS Omega
December 2024
School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, Hubei, P. R. China.
Design and synthesis of high-performance single-molecule magnets (SMMs) have long been a research focus. Inspired by the best dysprosium(III) metallocene SMMs and dysprosium(III) bis(methanediide) SMMs, we assumed dysprosium SMMs, which had electrical neutrality by combining the two types of ligands. As the Dy center is coordinated by one (substituted-)cyclopentadienyl (Cp) ligand and one methanediide ({C(PPhNSiMe)}) ligand on the axial sites, this ideal structure with linear C-Dy-Cp would strengthen the magnetic anisotropy and exhibit excellent SMM properties.
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