[Ru(2)(μ-O(2)CCH(3))(4)(MeOH)(2)](PF(6)) reacts with chiral diphosphines (R,R)- and (S,S)-chiraphos, leading to disassembly and production of the enantiomers Λ-[Ru(η(2)-O(2)CCH(3))(η(2)-(R,R)-chiraphos)(2)](PF(6)) and Δ-[Ru(η(2)-O(2)CCH(3))(η(2)-(S,S)-chiraphos)(2)](PF(6)) in high yield and purity. X-ray crystallography and solid-state circular dichroism (CD) show that only the indicated isomers are present in the solid state. Solution CD measurements also indicate their predominance in solution.
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http://dx.doi.org/10.1021/ic202013m | DOI Listing |
J Am Chem Soc
December 2024
State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
The homogeneous catalytic hydrogenation of benzo-fused heteroarenes generally provides partially hydrogenated products wherein the heteroaryl ring is preferentially reduced, such as quinoline hydrogenation, leading to 1,2,3,4-tetrahydroquinoline. Herein, we report a carbocycle-selective hydrogenation of fused -heteroarenes (quinoline, isoquinoline, quinoxaline, etc.) using the Ru complex of a chiral spiroketal-based diphosphine (SKP) as the catalyst, affording the corresponding 5,6,7,8-tetrahydro products in high chemoselectivities.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Institute of Molecular Functional Materials, State Key Laboratory of Synthetic Chemistry, and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, 999077, P. R. China.
J Org Chem
December 2024
Université de Bourgogne, UFR des Sciences et Techniques, ICMUB UMR-CNRS 6302, BP 47870, 21078 Dijon Cedex, France.
Chiral diphosphines with a biphenyl bridge and the chirality borne by the phosphorus atoms and not due to the atropoisomery of the biaryl backbone have been scarcely studied. Herein, we report the asymmetric synthesis of the (,)-2,2'-bis(ferrocenylphenylphosphino)biphenyl (BipheP*) ligand and its application in Rh-catalyzed hydrogenation. The synthesis was based on the enantioselective preparation of P-chirogenic ferrocenyl(-bromophenyl)phenylphosphine by the reaction of -phosphine-borane with 1,2-dibromobenzene and its homocoupling into BipheP*.
View Article and Find Full Text PDFJ Am Chem Soc
September 2024
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China.
The transition metal-catalyzed asymmetric hydrogenation (AH) of ketones to produce enantioenriched alcohols is an important reaction in organic chemistry with applications in the pharmaceutical and agrochemical fields. Using earth-abundant, biorelevant cobalt as the central metal in the catalyst has a high potential to improve sustainability and achieve hydrogenation reactions that are scalable. However, due to the high d-electron count, designing cobalt catalysts that exhibit turnover numbers (TONs, ≥1000) and enantioselectivities (≥90%) sufficient for synthetic utility and practical scalability (≥1 kg scale) remains a challenge.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States.
The first example of circularly polarized luminescence (CPL) from a molecular americium (Am) complex is reported. Coordination of Am(III) by a combination of thenoyltrifluoroacetonate and a chiral diphosphine oxide ligand yielded a complex with strong sensitized metal-centered luminescence. The energy transfer process for sensitization appears to occur via a unique resonant pathway, which results in the removal of the overlap between ligand phosphorescence and sensitized Am luminescence that has often been observed.
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