An anthranilamide-substituted borane [H-B(aam)]: its stability and application to iridium-catalyzed stereoselective hydroboration of alkynes.

A new anthranilamide-substituted borane [H-B(aam)] was synthesized and found to serve as a stable, easy-to-handle substitute for H-B(pin). It was applied to the direct synthesis of diverse linear (E)-alkenyl-B(aam)s via regio- and stereoselective hydroboration of terminal alkynes under iridium catalysis. A boryliridium hydride complex arising from the oxidative addition of H-B(aam) to the Ir catalyst was isolated and characterized via NMR studies.

Canonical translation-modulating OFF-riboswitches with a single aptamer binding to a small molecule that function in a higher eukaryotic cell-free expression system.

We have found that OFF-riboswitches that ligand-dependently downregulate the canonical translation in a higher eukaryotic expression system (wheat germ extract) can be easily created by inserting a single aptamer into the 5' untranslated region (UTR) of mRNA, even if its ligand is as small as theophylline. The key is the position of the inserted aptamer: the 5' end (+0 position) is much better than other positions for inhibiting canonical translation with the aptamer-ligand complex. The data showed that ribosome loading is suppressed by a rigid structure in the 5' end, and this suppression is dependent on the structure's stability but not on its size.

Ligand-responsive upregulation of 3' CITE-mediated translation in a wheat germ cell-free expression system.

We have rationally constructed a novel regulation-type of artificial riboswitch that ligand-dose dependently upregulates translation initiation mediated by a 3' cap-independent translation element (3' CITE) with no major hybridization switches in a plant expression system (wheat germ extract).