6332-04-3Relevant articles and documents
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Okubo,M.
, p. 2379 - 2384 (1977)
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Enantioselective Ring Opening of meso-Epoxides with Silicon Tetrachloride Catalyzed by Pyridine N-Oxides Fused with the Bicyclo[3.3.1]nonane Framework
Neni?kis, Algirdas,Ston?ius, Sigitas
, p. 6359 - 6369 (2015/10/06)
The synthesis of new chiral Lewis basic organocatalysts that contain pyridine N-oxide moieties fused with the bicyclo[3.3.1]nonane framework is reported. The obtained pyridine N-oxides were employed as catalysts in the enantioselective ring opening of meso-epoxides with silicon tetrachloride. Derivative 1b endowed with two 2,4-diaryl-substituted pyridine N-oxide moieties proved to be a particularly effective catalyst for desymmetrization of norbornene oxide 16i to furnish Wagner-Meerwein rearrangement product 20i in unprecedented 96 % ee. Difunctional congener 3, which is striped of the 4-aryl substituents, exhibited moderate to high levels of asymmetric induction (47-88 % ee) with alicyclic epoxide substrates. Chiral Lewis basic catalysts with pyridine N-oxide moieties fused with a bicyclo[3.3.1]nonane framework were used in the enantioselective ring opening of meso-epoxides. 2,4-Diaryl-substituted N-oxide exhibited excellent asymmetric induction with norbornene oxide (96 % ee), whereas less-substituted congener was most effective with alicyclic epoxide substrates (47-88 % ee).
Chiral bidentate phosphabenzene-based ligands: Synthesis, coordination chemistry, and application in Rh-catalyzed asymmetric hydrogenations
Müller, Christian,López, Leire Guarrotxena,Kooijman, Huub,Spek, Anthony L.,Vogt, Dieter
, p. 2017 - 2020 (2007/10/03)
Novel hydroxy-functionalized phosphabenzenes were synthesized, which provide the possibility to prepare chiral phosphabenzene-phosphites. These systems act as bidentate ligands toward rhodium centers and the corresponding metal complexes were applied in t