Atropo-diastereoselective cleavage of configurationally unstable biaryl lactones with alkali metal activated primary 1-arylethylamines

The atropo-diastereoselective cleavage of lactone-bridged and thus configur ationally unstable biaryls with chiral metal-activated 1-arylethylamines gi ves axially chiral biaryl amides in good yields and high atropo-diastereome ric ratios of up to 95:5. In this methodology, even the minor not desired r otational isomer can be recycled literally by recyclization back to the con figurationally unstable lactone, and renewed stereoselective cleavage. Furt hermore, by the use of the corresponding enantiomer of the N-nucleophile, t he enantiomeric biaryl product is also attainable from the same lactone pre cursor ("atropo-divergence"). In addition, several methods have been develo ped to transform the amide function into a methyl or an aminomethylene grou p. All these options further enlarge the scope and the utility of the metho d elaborated.