Versatile ruthenium complex "ruPCY" for directed catalytic hydrogen management in organic synthesis

Abstract

The ruthenium (Ru) precatalyst complex dichlorobis[2-[(dicyclohexylphosphino-κ P)methyl]pyridine -κ N]ruthenium(II) (RuPCY), first developed by us, was shown to be useful not only for the catalytic hydrogenation of inert carboxylic acid derivatives including amides and esters, but also for the catalytic dehydrogenation of primary (1°) and secondary (2°) alcohols and subsequent reactions. RuPCY is versatile, and different Ru catalysts derived therefrom are quite useful for realizing a variety of indiscrete/discrete catalytic hydrogen management (HyMA) reactions. The sequential use of different starting materials and different catalysts (all derived from RuPCY) permits otherwise challenging orthogonal HyMA processes. This accommodates, for example, a salt-free access and/or shortcut to synthetic intermediates of pharmaceutically important substances such as donepezil (Aricept®) and atorvastatin (Lipitor®).