Chiral Tricationic Tris(1,2-diphenylethylenediamine) Cobalt(III) Hydrogen Bond Donor Catalysts with Defined Carbon/Metal Configurations; Matched/Mismatched Effects upon Enantioselectivities with Enantiomeric Chiral Counter Anions

The enantiopure and diastereopure salts Lambda- or Delta-[Co((S,S)-dpen)(3)](3+) 2Cl(-)BAr(f)(-) (Lambda- or Delta-(S,S)-1(3+) 2Cl(-)BAr(f)(-); dpen/BArf = 1,2-diphenylethylenediamine/B(3,5-C6H3(CF3)(2))(4)) and Lambda-(S,S)-1(3+) 3Cl(-) are treated with salts of the enantiopure chiral monoanions (A(-)) or dianions (A(2-)) 3-bromocamphor-8-sulfonate (camphSO(3)(-)), 1,1'-binaphthyl-2,2'-diyl phosphate (and three 3,3'-disubstituted derivatives), a related biphenanthryl species, tartrate, and Sb-2(tare)(2)(2-) (tart' = [-O2C-CHO--CHO--CO2-]). The lipophilic salts Lambda- or Delta-(S,S)-1(3+) 2A(-)BAr(f)(-), Lambda-(S,S)-1(3+) A(2-)BAr(f)(-), and Lambda-(S,S)-1(3+) 3A(-) are isolated as hydrates and characterized by NMR and microanalyses. In the presence of tertiary amines, many of these are highly enantioselective catalysts for additions of 1,3-dicarbonyl compounds to trans-beta-nitrostyrene and di-tert-butylazodicarboxylate. The ee values for diastereomeric salts can exhibit significant differences (avg/high/median Delta(%ee) = 10/63/6; matched/mismatched effect), and in a few cases, they are better than those obtained with Lambda- or Delta-(S,S)-1(3+) 2Cl(-)BAr(f)(-). The crystal structure of Delta-(S,S)-1(3+) 2(1S)-camphSO(3)(-)BAr(f)(-) shows that the two sulfonate moieties hydrogen-bond to opposite (idealized) C-3-symmetric faces of the trication, with a separate oxygen atom associated with each of the three synperiplanar NH groups.