Face off: The rutheniumcomplexes of a new axially chiral PNN ligand (L) are highly efficient in the presence of dimethylsulfoxide (DMSO) for hydrogenation of both functionalized and unfunctionalized tert‐alkyl ketones. DMSO is thought to narrow down the many possible complex stereoisomers into a single facial L/Ru complex, thus enhancing the reactivity, selectivity, and productivity.
The aldol-type condensation of enantiomericallypure α-sulphinylacetamides is described. The stereochemical outcome of the reaction mainly depends on the nature of the base used to generate the enolate. Experimental evidences allow the identification of preferred reaction paths.
A directcatalyticasymmetricaldolreaction of thioamides with a soft Lewis acid/hard Brønsted base cooperative catalytic system comprising (R,R)-Ph-BPE/[Cu(CH(3)CN)(4)]PF(6)/LiOAr is described. Highly chemoselective deprotonative activation of thioamides allows for a directaldolreaction of alpha-nonbranched aliphatic aldehydes, which are susceptible to self-condensation. Facile reduction of the
Enantiomericallypure P-tolyl sulphinyl-N,N-dimethylthioacetamide (1) was prepared starting from (-)-(S)-menthyl toluene-p-sulphinate. Aldol-type condensation of (1) and subsequent removal of the Sulphinyl group open an entry to optically active β-hydroxy thioacetamides in 40–90% e.e.