Design, synthesis and catalytic properties of chiral counteranions on transition metal catalysts: A new route to asymmetric induction

The design of enantioselective transition metal catalyzed reactions is an important area of chemical research. The purpose of this study was to develop a new method to incorporate chirality into transition metal catalysis via ion pairing interactions. This has led to the development of the first enantioselective transition metal catalyzed reaction using a chiral counteranion as the sole source of asymmetry.; In chapter two, the synthesis of a chiral bis(1,1′-bi-2-naphtholato)borate anion is described. This anion can be incorporated into cationic copper(I) complexes via anion exchange, which has allowed its effect on the copper(I) catalyzed aziridination and cyclopropanation reactions to be examined. In the cyclopropanation reaction, it was found that changing the chirality of the counteranion in the presence of (R,R)-2,2′-isopropylidenebis(4-phenyl-2-oxazoline), a chiral ligand, results in a change in the enantioselectivity of the cyclopropanes formed by over 30%. The influence of the chiral counteranion in the absence of a chiral ligand was also explored.; Chapter three describes the use of the copper(I) bis((R)-1,1′ -bi-2-naphtholato) borate salt as a chiral NMR shift reagent. The coordination of the (R) and (S) enantiomers of 2,2′-bis(di-p-tolyl-phosphino)-1,1 ′-binaphthyl (tol-BINAP) to copper(I) bis((R)-1,1′ -bi-2-naphtholato) borate in CD₂Cl₂ results in well resolved 1H NMR (400 MHz) resonances for the two enantiomers. Examination of standard solutions of 2,2′-bis(di-p-tolyl-phosphino)-1,1 ′-binaphthyl demonstrate that the copper complex can be used as an effective NMR shift reagent over a wide range of enantiomeric compositions.; In chapters four and five, the synthesis of a new class of peptide-based chiral counteranions, and their incorporation into copper(I) catalysts via ion exchange, is described. Studies on the copper(I) catalyzed cyclopropanation of styrene with ethyl diazoacetate demonstrate that ion-pairing with these anions can provide a novel method to incorporate a copper cation into a chiral α-amino acid environment for asymmetric catalysis. (Abstract shortened by UMI.)...