Development of a new class of (1S,3R,4R)-2-azabicyclo[2.2.1]heptane-oxazoline ligands and their application in asymmetric transfer hydrogenation

Mechanistic insights for the transprotection of tertiary amines with Boc2O via charged carbamates: access to both enantiomers of 2-azanorbornane-3-exo-carboxylic acids

Development of a synthetic methodology for the selective transprotection in hindered tertiary amines using Boc₂O under N–C hydrogenolysis catalyzed by Pd/C: access to both enantiomers of 2-azanorbornane-3-exo-carboxylates.

2-Azanorbornane--a versatile chiral aza-Diels-Alder cycloadduct: preparation, applications in stereoselective synthesis and biological activity

The review presents the achievements in the field of preparation of chiral 2-azanorbornyl derivatives and their application in various stereoselective reactions as well as in biomimetic studies.

Modular syntheses of oxazolinylamine ligands and characterization of group 10 metal complexes

The syntheses of aminoalkyloxazoline and pyrrolidinyloxazoline ligands, each of which bear a pair of chiral centres, by both known and new routes are reported. Variable temperature NMR studies show that the known stepwise syntheses of the pyrrolidinyl compounds are not complicated by epimerization; however, coordination of one of the aminoalkyl derivatives to Pt(II) under conditions of prolonged heating to 80 °C does give mixtures of diastereomeric N,N ′-chelated complexes that result from inversion of the chiral centre associated with the aminoalkyl fragment. A new synthesis of pyrrolidinyloxazoline ligands that involves the Zn-catalyzed cyclization of Cbz-protected 2-cyanopyrrolidine and β-amino alcohols is also reported. This procedure offers the advantages of economy, shorter time, and fewer purification steps over the previously reported synthesis. In addition, the crystal structure of an enantiopure Pd(II) complex of an N,N ′-chelated pyrrolidinyloxazoline is disclosed. This compound has a pseudo-C2 axis of symmetry, which may make it suitable for asymmetric catalytic applications.Key words: chiral ligands, ligand design, oxazolines, variable temperature NMR spectroscopy, asymmetric catalysis, coordination compounds, palladium, platinum

Asymmetric Hydrogenation of Imines and Olefins Using Phosphine-Oxazoline Iridium Complexes as Catalysts

Herein we describe the synthesis of a new class of chiral phosphine-oxazolines and their application as ligands in iridium-catalyzed hydrogenations. Mechanistic aspects of olefin hydrogenation with this class of iridium catalysts are discussed and a selectivity model to help rationalize the results obtained is also presented.

Application of Phosphine−Oxazoline Ligands in Ir-Catalyzed Asymmetric Hydrogenation of Acyclic AromaticN-Arylimines

[reaction: see text] A new class of chiral phosphine-oxazoline ligands have been developed. Chiral Ir complexes prepared from these ligands induced high enantioselectivities (66-90% ee) when applied to the asymmetric hydrogenation of acyclic aromatic N-arylimines.