Mimics of the self-assembling chlorosomal bacteriochlorophylls: regio- and stereoselective synthesis and stereoanalysis of acyl(1-hydroxyalkyl)porphyrins.

Diacylation of copper 10,20-bis(3,5-di-tert-butylphenylporphyrin) using Friedel-Crafts conditions at short reaction times, high concentrations of catalyst, and 0-4 degrees C affords only the 3,17-diacyl-substituted porphyrins, out of the 12 possible regioisomers. At longer reaction times and higher temperatures, the 3,13-diacyl compounds are also formed, and the two isomers can be conveniently separated by normal chromatographic techniques. Monoreduction of these diketones affords in good yields the corresponding acyl(1-hydroxyalkyl)porphyrins, which after zinc metalation are mimics of the natural chlorosomal bacteriochlorophyll (BChl) d.

Atroposelective biaryl coupling with chiral catalysts: total synthesis of the antileishmanial naphthylisoquinoline alkaloids ancistrotanzanine B and ancistroealaine A.

[reaction: see text] The first total synthesis of the naphthylisoquinoline alkaloid ancistrotanzanine B and its atropo-diastereomer, ancistroealaine A, is described. The key step is the construction of the rotationally hindered and thus stereogenic biaryl axis by Suzuki coupling. While only weak internal asymmetric inductions by the stereogenic center in the dihydroisoquinoline part were observed, much better atropisomeric ratios in favor of ancistrotanzanine B were achieved by the use of chiral catalysts.