Highly enantioselective aminoacylase-catalyzed transesterification of secondary alcohols

2-(Aminomethyl)-oxazolines: Highly Modular Scaffolds for the Preparation of Novel Asymmetric Ligands

Highly modular chiral 2-(aminoalkyl)oxazolines have been prepared from alpha-amino acids and 1,2-amino alcohols. The amine-functionalized oxazolines were employed as scaffolds in the preparation of a number of different ligands with potential denticities varying from 2 to 5. The obtained ligands were employed and evaluated in the ruthenium-catalyzed asymmetric transfer-hydrogenation of acetophenone and in the titanium-catalyzed addition of diethylzinc to aldehydes. In the latter process, enantioselectivity up to 97% was obtained.

Crude aminoacylase fromaspergillus sp. is a mixture of hydrolases

A range of cross-linked enzyme aggregates (CLEAs) was prepared from commercially available aminoacylase I. Results from three test reactions showed that aminoacylase does not possess aminolysis or alcoholysis activity, both previously ascribed to this enzyme. This result was confirmed using aminoacylase purified by chromatographic techniques, which leads us to conclude that the previously observed acylations of esters and amines is due to other enzymes present as impurities in the crude aminoacylase I.

4-(Benzoylindolizinyl)butyric acids; novel nonsteroidal inhibitors of steroid 5alpha-reductase. III

A novel series of indolizinebutyric acids with various benzoyl substituents was synthesized to develop nonsteroidal inhibitors of steroid 5alpha-reductase, and the structure-activity relationships in this series were studied. We previously reported the structure-activity relationships in a series of indolebutyric acids as well as the discovery of the novel nonsteroidal 5alpha-reductase inhibitor, FK143. We have now made other modifications to this compound to improve in vivo inhibitory activity. By altering the heterocyclic nucleus and changing the benzoyl substituent we have succeeded in identifying the strongly active compound, FK687, (S)-4-[1-[4-[[1-(4-isobutylphenyl)butyl]oxy]benzoyl]indolizin-3-yl]butyric acid, which displays strong in vitro inhibitory activity against the human enzyme and in vivo inhibitory activity against the castrated young rat model. This compound should be a useful agent for the treatment of benign prostatic hyperplasia.