Synthesis of non-symmetric bis(oxazoline)-containing ligands and their application in the catalytic enantioselective Nozaki–Hiyama–Kishi allylation of benzaldehyde

Abstract

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%.