Chiral Cobalt(III) Tris(1,2-diamine) Catalysts That Incorporate Nitrogenous Base Containing Anions for the Bifunctional Activation of Nucleophiles and Electrophiles in Enantioselective Addition Reactions

( )The lipophilic diastereomeric cobalt complexes Lambda or Delta-[Co((S,S)-dpen)(3)](3+) 2Cl(-) BArf- (Lambda or Delta-(S,S)-2(3+) 2Cl(-)BAr(f)(-); dpen/BArf- = 1,2-diphenylethylenediamine/B(3,5-C6H3(CF3)(2))(4)(-)) catalyze a number of enantioselective C-H bond addition reactions in the presence of aliphatic tertiary amines, but pyridine and N,N-dimethylaniline are much less effective. However, when these bases are incorporated into counter anions (4(-)) as in Lambda or Delta- (S,S) 2(3+) 4(-)Cl(-) BArf-, highly enantioselective bifunctional catalysts can be realized. Salts of nicotinates, isonicotinates, related sulfonates, and N,N-dimethylaminobenzoate are effective. The 6-chloronicotinate salt gives slower rates and lower ee values, and the 6-aminonicotinate salt gives faster rates and higher ee values. The 6-methyl, 2-methoxy, and unsubstituted analogs afford intermediate results. The 6-aminonicotinate catalyst is applied to additions of dimethyl malonate to 14 aryl- substituted nitroolefins and additions of 6 1,3-dicarbonyl compounds to di-t-butyl azodicarboxylate, with average yields/ee values of 90%/85% and 94%/77%, respectively. The authors are unaware of other ionic catalysts for which Bronsted bases have been productively incorporated into the anions, which are seldom if ever purposefully functionalized in any manner.