All four possible diastereoisomers of phosphinoferrocenyloxazoline (Phosferrox type) ligands containing three elements of chirality were synthesized as single enantiomers. The configured oxazoline moiety (R = Me, -Pr) was used to control the generation of planar chirality by lithiation, with the alternative diastereoisomer formed by use of a deuterium blocking group. In each case subsequent addition of PhPCl followed by -TolMgBr resulted in a single -stereogenic diastereoisomer (,, and ,,, respectively). The alternative diastereoisomers were formed selectively by addition of -TolPCl followed by PhMgBr ((,, and ,,, respectively). Preliminary application of these four ligand diastereoisomers, together with (,) and (,) Phosferrox (PPh), to palladium catalyzed allylic alkylation of -1,3-diphenylallyl acetate revealed a stepwise increase/decrease in ee, with the configuration of the matched/matched diastereoisomer as ,, (97% ee).
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