Self-assembled organic–inorganic hybrid silica with ionic liquid framework: a novel support for the catalytic enantioselective Strecker reaction of imines using Yb(OTf)3–pybox catalyst
作者:Babak Karimi、Aziz Maleki、Dawood Elhamifar、James H. Clark、Andrew J. Hunt
DOI:10.1039/c0cc01426e
日期:——
Yb(OTf)3âpybox is immobilized in a novel self-assembled ionic liquid hybrid silica and has been successfully applied as a catalyst for the asymmetric Strecker hydrocyanation of aldimines. This catalytic system can be reused for at least 6 times without any significant loss of activity and enantioselectivity.
Catalytic asymmetric Strecker hydrocyanation of imines using Yb(OTf)3–pybox catalysts
作者:Babak Karimi、Aziz Maleki
DOI:10.1039/b908854g
日期:——
We have explored the highly enantioselective Strecker hydrocyanation of a wide range of aromatic, α,β-unsaturated, heterocyclic, and aliphatic aldimines with good to excellent conversions and ees up to 98% in the presence of catalytic amounts of Yb(OTf)3âpybox complexes.
coupling with 4-bromo-2,6-bis[(R)-4-phenyloxazolin-2-yl]pyridine and the resulting pybox derivatives were immobilized on Tentagel resins. Ytterbium(III) chloride complexes of the polymeric ligands catalyzed the addition of trimethylsilylcyanide to benzaldehyde with 80-81% ee. The ligands were reused more than 30 times without any loss in selectivity or activity, and the metal complexes could be recovered
Two-Photon Circularly Polarized Luminescence of Chiral Eu Complexes
作者:Oliver G. Willis、Filippo Petri、Davide F. De Rosa、Alessandro Mandoli、Robert Pal、Francesco Zinna、Lorenzo Di Bari
DOI:10.1021/jacs.3c05957
日期:2023.11.22
We report the synthesis of chiral lanthanide complexes with extended π conjugation for efficient circularly polarized luminescence (CPL) via two-photon excitation (2PE). The pyridine bis-oxazoline (PyBox) core provides the chiral Ln3+ environment, while the extension of the conjugated backbone through the pyridine 4-position with a phenylacetylene unit increases the two-photon absorption cross section