Rhodium(III)-Catalyzed Atroposelective Indolization to Access Planar-Chiral Macrocycles.

Macrocycles incorporating conformationally defined indoles are widely found in bioactive natural products. However, the catalytic enantioselective synthesis of planar-chiral indoles via indolization involving macrocyclization remains elusive. Herein, we present the first rhodium(III)-catalyzed atroposelective macrocyclization, which involves the C-H activation of aniline, and a subsequent oxidation [3 + 2] annulation reaction with an intramolecular alkyne.

An Approach for Highly Enantioselective Synthesis of -Disubstituted []Paracyclophanes.

Atroposelective synthesis of -disubstituted []paracyclophanes is a difficult task in organic chemistry. We describe a facile approach for the synthesis of -disubstituted []paracyclophanes using Pd-catalyzed enantioselective C-H olefination and sequential reductive cleavage. A wide range of []paracyclophanes was obtained with excellent enantioselectivity.

A convenient correspondence between k-mer-based metagenomic distances and phylogenetically-informed β-diversity measures.

k-mer-based distances are often used to describe the differences between communities in metagenome sequencing studies because of their computational convenience and history of effectiveness. Although k-mer-based distances do not use information about taxon abundances, we show that one class of k-mer distances between metagenomes (the Euclidean distance between k-mer spectra, or EKS distances) are very closely related to a class of phylogenetically-informed β-diversity measures that do explicitly use both the taxon abundances and information about the phylogenetic relationships among the taxa. Furthermore, we show that both of these distances can be interpreted as using certain features of the taxon abundances that are related to the phylogenetic tree.