Chiral precursors Λ-[Ir(ppy)2(l-pro)] (Λ-L, where ppy is 2-phenylpyridine; pro is proline), Λ-[Ir(ppy)2(MeCN)2](PF6) (Λ-1), Δ-[Ir(ppy)2(d-pro)] (Δ-D), and Δ-[Ir(ppy)2(MeCN)2](PF6) (Δ-1) were synthesized from rac-[(Ir(ppy)2)2Cl2] and l-pro or d-pro by means of the auxiliary ligand strategy with 99% de values. The enantiopure mono complexes Λ/Δ-[Ir(ppy)2(L)](PF6) (L is 2,2'-bipyridine, Λ/Δ-2; L is 2,2'-dipyrimidine (dpm), Λ/Δ-3; L is 2,2'-bibenzimidazole (H2bbim), Λ/Δ-4) with 99% ee values and binuclear complexes ΛΛ/ΔΔ-[(Ir(ppy)2)2(dpm)](PF6)2 (ΛΛ-5 and ΔΔ-5) and ΛΛ/ΔΔ-[(Ir(ppy)2)2(bbim)] (ΛΛ-6 and ΔΔ-6) with 99% de values were synthesized in one step using the corresponding chiral precursors. The absolute configurations at Ir(III) centers of precursor Δ-1, mononuclear Λ-3, and binuclear ΔΔ-6 were confirmed by single-crystal structural analysis and characterized by circular dichroism (CD) spectroscopy. The correlation between the absolute configuration at Ir(III) center and CD spectra was established. The configurations at Ir(III) centers are stable during the reactions, and the chiral precursors can be used for the asymmetric synthesis of enantiomerically pure mono- and polynuclear Ir(III) complexes. Moreover, meso ΛΔ-[(Ir(ppy)2)2(dpm)](PF6)2 (meso-5) and ΛΔ-[(Ir(ppy)2)2(bbim)] (meso-6) were also synthesized using these precursors.
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http://dx.doi.org/10.1021/acs.inorgchem.6b00527 | DOI Listing |
J Chem Theory Comput
January 2025
Physics Postgraduate Program, Institute of Physics, University of Brasília, 70910-900 Brasília-DF, Brazil.
Two-dimensional (2D) nanomaterials are at the forefront of potential technological advancements. Carbon-based materials have been extensively studied since synthesizing graphene, which revealed properties of great interest for novel applications across diverse scientific and technological domains. New carbon allotropes continue to be explored theoretically, with several successful synthesis processes for carbon-based materials recently achieved.
View Article and Find Full Text PDFSheng Wu Gong Cheng Xue Bao
January 2025
College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China.
In China, the crude oil supply is highly dependent on overseas countries, and thus strengthening crude oil self-sufficiency has become an important issue of the national energy security. Tertiary oil recovery, especially polymer flooding, has been widely applied in large oil fields in China, which can increase the recovery rate by 15%-20% compared with water flooding. However, the widely used oil flooding polymers show poor thermal stability and salinity tolerance, complicated synthesis ways of monomers, and environmental unfriendliness.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
State Key Laboratory of Green Pesticide, Fine Chemical Research and Development Center, Guizhou University, Huaxi District, Guiyang 550025, China.
Herein, we developed a practical approach using stable, cost-effective ammonium salts with an organic base to generate anhydrous ammonia for asymmetric sulfinylation, achieving a broad range of enantioenriched sulfinamides with excellent yields and optical purity. Additionally, these sulfinamide products serve as versatile precursors for S-stereogenic functional molecules with potential in organic synthesis and drug discovery.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.
Chiral medium-sized rings, albeit displaying attractive properties for drug development, suffer from numerous synthetic challenges due to difficult cyclization steps that must take place to form these unusually strained, atropisomeric rings from sterically crowded precursors. In fact, catalytic enantioselective cyclization methods for the formation of chiral seven-membered rings are unknown, and the corresponding eight-membered variants are also sparse. In this work, we present a substrate preorganization-based, enantioselective, organocatalytic strategy to construct seven- and eight-membered rings featuring chirality that is intrinsic to the ring in the absence of singular stereogenic atoms or single bond axes of chirality.
View Article and Find Full Text PDFJ Org Chem
January 2025
School of Chemistry, University of Hyderabad, Hyderabad 500 046, Telangana, India.
Aldolases, especially 2-deoxyribose-5-phosphate aldolase (DERA) enzymes, have been widely employed to access key chiral precursors for various active pharmaceutical ingredients (APIs). This has been enabled by expanding their substrate scope toward non-natural acceptors and donors via protein engineering. In this study, we endeavored to broaden the acceptor substrate scope of DERA from sp.
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