MOP: Design, preparation, and use for palladium-catalyzed asymmetric reactions

Axially chiral monophosphines, 2-(diphenylphosphino)-1,1'-binaphthyl (MOPs, 1) were prepared starting with homochiral 2,2'-dihydroxy-1,1'-binaphthyl. The palladium complexes coordinated with the MOP ligands are highly effective catalysts for several types of catalytic asymmetric reactions where chelating bisphosphine ligands can not be used because of their low catalytic activity or low selectivity towards the desired reaction pathway. Typical examples of the catalytic asymmetric reactions are as follows: 1) Asymmetric hydrosilylation of alkyl-substituted terminal olefins and bicycle[2.2.1] heptene derivatives giving, after oxidation, optically active alcohols (up to 98% ee). 2) Asymmetric reduction of allylic esters with formic acid (up to 93% ee.