209850-70-4Relevant academic research and scientific papers
Coupling of bulky, electron-deficient partners in aryl amination in the preparation of tridentate bis(oxazoline) ligands for asymmetric catalysis
McManus, Helen A.,Guiry, Patrick J.
, p. 8566 - 8573 (2002)
A new class of tridentate bis(oxazoline) ligands 7, in which an N-phenylaniline unit links the two oxazoline rings, has been prepared. The key step in their synthesis is a Hartwig-Buchwald type Pd-catalyzed aryl amination between the two bulky o-substituted coupling partners, 2-(2′-bromophenyl)oxazolines 8 and 2-(o-aminophenyl)oxazolines 9. By varying the substituent on the coupling partners, a range of 10 ligands has been prepared in good yield. During the synthesis of 2-(o-aminophenyl)oxazolines 9a-d, a number of products of unexpected side reactions were isolated in two of the three steps. Alternatively, the required 2-(o-aminophenyl)oxazolines 9 were obtained by a DAST-promoted cyclodehydration of hydroxyamides 12a-d without formation of any byproducts.
Synthesis of chiral bis(dihydrooxazolylphenyl)oxalamides, a new class of tetradentate ligands for asymmetric catalysis
End, Nicole,Macko, Ludwig,Zehnder, Margareta,Pfaltz, Andreas
, p. 818 - 824 (2007/10/03)
Enantiomerically pure N,N'-bis[2-(4,5-dihydrooxazol-2-yl)phenyl]oxalamides are readily prepared from 2-(2-aminophenyl)-4,5-dihydrooxazoles and oxalyl chloride. The structures of the corresponding nickel and copper complexes were determined by X-ray analys
