Abstract
1. A novel one-pot three-component catalytic enantioselective reaction between bis(pinacolato)diboron, enals and 2-(triphenylphosphoranylidene)acetate esters employing inexpensive bench stable Cu salts and simple chiral amine as co-catalysts is presented. The reaction proceeds via a tandem catalytic asymmetric conjugate borane addition/Wittig sequence where the b-boration step is 1,4-selective and gives the corresponding homoallylboronate products with high enantiomeric ratios (up to 97.5:2.5 er).
2. The direct intermolecular regiospecific and highly enantioselective a-allylic alkylation of linear aldehydes by combination of achiral bench stable Pd(0) complexes and simple chiral amines as co-catalysts is disclosed. The co-catalytic asymmetric chemoselective and regiospecific a-allylic alkylation reaction is linked in tandem with in situ reduction to give the corresponding 2-alkyl alcohols with high enantiomeric ratios (up to 98:2 er). It is also an expeditious entry to valuable 2-alkyl substituted hemiacetals and 2-alkyl-butane-1,4-diols.