Results 141 to 150 of about 166,370 (359)

Dual-Mode Thio-MacMillan Organocatalysts: Stereoselective Diels-Alder Reactions or Sacrificial Self-Cyclization to N-Bridged Bicyclic Lactams. [PDF]

open access: yesChemistry
The study of the Diels–Alder reaction of cinnamaldehyde and cyclopentadiene, catalyzed by chiral imidazolidine‐4‐thiones, led to the discovery of a highly regio‐ and stereoselective Michael‐addition and consecutive ring closure. Here, the imidazolidine‐4‐thione not only catalytically activates cinnamaldehyde but also participates as the nucleophile to ...
Ebeling MSR   +5 more
europepmc   +2 more sources

Synthese des 18F-markierten Coenzyms Uridindiphosphatglucose als Basis für die 18F-Glykosylierung von Glykoproteinen [PDF]

open access: yes, 2000
The chemo-enzymatic radiosynthesis of no carrier added (n.c.a.) uridine diphospho-2-deoxy- 2-[$^{18}$F]fluoro-$\alpha$-D-glucose (UDP-[$^{18}$F]FGlc) was developed.
Prante, Olaf
core  

Aluminum versus Gallium: Differences in Bis(bis(trimethylsilyl)methyl) Element Halides, Hydrides, and Oxygen‐Bridged E/P Frustrated Lewis Pairs

open access: yesChemistryEurope, EarlyView.
Reacting Bis2GaBr (Bis = CH(SiMe3)2) with Bis2AlH selectively yields Bis2GaH, a monomeric hydride in solution, characterized by diffusion ordered spectroscopy NMR, infrared spectroscopy and indirectly via hydrogallation. A one‐pot route enables frustrated Lewis pairs Bis2EOPtBu2 (E = Al, Ga), with the gallium analog splitting H2 and showing a dynamic ...
Julian Buth   +7 more
wiley   +1 more source

Research Progress of Polyoxometalate‐Integrated Frameworks: Syntheses, Properties, and Applications

open access: yesChemistryEurope, EarlyView.
This review systematically summarizes the integration of polyoxometalates with covalent organic frameworks, metal‐organic frameworks, hydrogen‐bonded organic frameworks, and emerging porous hosts. It highlights synergistic effects, synthesis strategies, and applications in catalysis, energy storage, sensing, and biomedicine, while addressing current ...
De‐Yin Wang   +6 more
wiley   +1 more source

Stereospecific Transition-Metal-Free Alkylation of Chiral Non-Racemic Secondary Tosylates with Cyanohydrins: Convenient Access to Enantiomerically Enriched α-Tertiary Ketones. [PDF]

open access: yesAngew Chem Int Ed Engl
A stereospecific, transition‐metal‐free SN2 alkylation of cyanohydrins with chiral non‐racemic secondary tosylates is reported, providing efficient access to enantioenriched α‐tertiary ketones. The method exhibits broad substrate scope, operational simplicity, and excellent stereospecificity, including stereoconvergent reactions of E/Z mixtures of ...
Ma J, Li H, Majhi J, Evans PA.
europepmc   +3 more sources

CuH‐Catalyzed Asymmetric Desymmetrization of Cyclobutenes via Stereodivergent Hydroamination

open access: yesChemistryEurope, EarlyView.
The CuH‐catalyzed stereodivergent hydroamination through asymmetric desymmetrization of cyclobutenes has been achieved, yielding a range of trisubstituted aminocyclobutanes with excellent results. A series of subsequent transformations, including the first asymmetric synthesis of two pharmaceutically active molecules, have been realized, and density ...
Xiang Lei   +8 more
wiley   +1 more source

Total Synthesis and Complete Stereochemical Assignment of Amphirionin‐5, a Potent Natural Osteoblasts Proliferator

open access: yesChemistryEurope, EarlyView.
The convergent total synthesis of a candidate diastereomer of amphirionin‐5 was accomplished in 22 steps via the coupling of the C1‐C16 enone segment and the C17‐C28 aldehyde segment using Stetter reaction. The overall stereochemistry of amphirionin‐5 was fully assigned, based on the comparison of spectroscopic and chiroptical data between the ...
Yusuke Ogura   +7 more
wiley   +1 more source

Control of Stereoselectivity in Diverse Hapalindole Metabolites is Mediated by Cofactor‐Induced Combinatorial Pairing of Stig Cyclases [PDF]

open access: bronze, 2020
Shasha Li   +9 more
openalex   +1 more source

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