Synthesis of non-symmetric bis(oxazoline)-containing ligands and their application in the catalytic enantioselective Nozaki-Hiyama-Kishi allylation of benzaldehyde.
We report the good to high-yielding three-step synthesis of non-symmetrical bis(oxazoline)-containing ligands possessing an N-thienylaniline unit. The convergent synthesis employed a palladium-catalysed aryl amination of 2-(2'-bromothiophene)nitrile as the key step, with sixteen ligands prepared in total. These ligands were subsequently applied in the chromium-catalysed enantioselective Nozaki-Hiyama-Kishi allylation of benzaldehyde with an optimal enantioselectivity of 73%.
Hargaden
Gráinne C
GC
Centre for Synthesis and Chemical Biology, UCD School of Chemistry and Chemical Biology, UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
O'Sullivan
Timothy P
TP
Guiry
Patrick J
PJ
D000814:Aniline Compounds / Q000737:chemistry; D001547:Benzaldehydes / Q000737:chemistry*; D002384:Catalysis; D002857:Chromium / Q000737:chemistry; D008024:Ligands; D010165:Palladium / Q000737:chemistry; D013237:Stereoisomerism; D013379:Substrate Specificity
D000814:Aniline Compounds; D001547:Benzaldehydes; D008024:Ligands; D002857:Chromium; D010165:Palladium; C023650:aniline; C032175:benzaldehyde