Atropo-diastereoselective coupling of aryllithiums and arynes — variations around the chiral auxiliary

Abstract The atropo-selective coupling of in situ generated arynes and aryllithiums bearing various chiral auxiliaries ortho to lithium ( tert -butylsulfoxide, para -tolylsulfoxide, tartrate-derived chiral diethers and oxazolines) is described. Chiral oxazolines showed the best results in terms of yields of coupling products. Different reaction parameters like the nature of the aryne precursor, the oxazoline, the alkyllithium base or the solvent revealed to be crucial for obtaining good yields and for diastereoselection.