Catalytic enantioselective borane reduction of arylketones with pinene-derived amino alcohols

Both cis- and trans-1,2-amino alcohols 5 and their N-alkylated derivatives 6 were prepared from (−)-α-pinene 7 as chirality source and utilized in asymmetric borane reduction of arylketones 12 employing a one-pot multi-substrate screening. The oxazaborolidine catalysts were generated in situ from amino alcohols 5 and 6 and trimethyl borate.