Aromatic donor-acceptor interaction promoted catalyst assemblies for hydrolytic kinetic resolution of epichlorohydrin.

Three generations of Co(iii)-salen complexes containing electron-deficient aromatic moieties (acceptors) have been synthesized. When electron-rich aromatic compounds (donors) were introduced, these complexes were designed to form catalyst assemblies through aromatic donor-acceptor interaction. For all three generations of complexes, the addition of a proper donor led to higher catalytic efficiency in the hydrolytic kinetic resolution (HKR) of epichlorohydrin. The reaction rates are in the following order: Generation 3 > Generation 2 > Generation 1. The aromatic donor-acceptor interaction was verified by NMR spectroscopy and UV-vis absorption spectroscopy studies. These results demonstrated that aromatic donor-acceptor interaction can be a valuable driving force in the assembly of supramolecular catalysts.

Straightforward synthesis of enantiopure (R)- and (S)-trifluoroalaninol.

Two efficient routes are reported for the synthesis of both enantiomers of trifluoroalaninol in enantiopure form. The first pathway involves a Strecker-type reaction performed from a chiral trifluoromethyloxazolidine (Fox). The second route, which is more direct, involves, as a key step, the reduction of chiral oxazolidines or imines derived from ethyl trifluoropyruvate.

In situ generation of novel acyclic diaminocarbene-copper complex.

A novel acyclic diaminocarbene-copper complex appears to be generated from a chloroamidinium salt and Cu(I)-thiophenecarboxylate in the presence of Grignard reagent based on (13)C NMR studies and is a highly efficient catalyst for S(N)2'-allylic alkylation.