A variety of functionalized chiral silicon molecules were stereoselectively synthesized from enantio-enriched chiral silanols or chiral silacyclopentenols, which were prepared by highly enantioselective desymmetrization reactions of achiral silicon molecules. The unique reactivity, and substantial bioactivity of the synthesized chiral silicon molecules were disclosed.

Activation of reactive intermediates using electron-acceptor moieties for increasing electrophilicity realized efficient transformations using organometallic reagents. The nucleophilic addition of organozinc reagents to electrophilic carbenoid intermediates derived from cyclopropenes generates allylmetal intermediates for subsequent allylation reactions of electrophiles. The control of neighboring boron atoms gives highly reactive intermediates for hydroboration and the Suzuki-Miyaura cross-coupling reaction. The design of multinuclear complexes provides excellent catalytic performances for the addition reaction of organozinc and organoaluminum reagents.

Metallo-enzymes catalyze a variety of chemical transformation reactions such as oxidation, reduction, coupling, and hydrolysis, most of which are essential for synthetic organic chemistry. Rieske dioxygenases, one of the most abundant nonheme iron enzyme family, catalyzes selective cis-dihydroxylation of arene C=C double bonds using molecular oxygen or hydrogen peroxide. The iron model complexes have so far been developed and employed in cis-dihydroxylation of alkenes as a catalyst. However, there are several drawbacks in the iron model systems such as stability, substrate limitation, low substrate and oxidant conversion, and low product selectivity. To make more efficient catalytic systems, the authors have developed osmium-complexes as the model compounds of the Rieske dioxygenase reaction center. Herein, the authors employ them as the catalyst for cis-dihydroxylation of alkenes. The active oxidant has been identified, and the catalytic mechanism has been explored based on the kinetic analysis and DFT calculations. Furthermore, the catalytic system has been applied to oxidative cyclization of 1,5-dienes to afford tetrahydrofuran derivatives and to aminohydroxylation of alkenes to give cis-1,2-aminoalcohols.

Thiophene-based organic D-π-A dyes exert various functions as sensitizers of dye-sensitized solar cells, p-type semiconductors of thin-film organic solar cells, and inhibitors of aggregation of amyloid-β and tau proteins those are regarded as promising drug targets of Alzheimer’s disease. This account describes rapid and systematic synthesis of thiophene-based organic D-π-A dyes via our developed, one-pot, cross-coupling approach and evaluation of their various functions in order to acquire high-quality structure-function relationship information.

Organic-based open-shell π-electronic molecules are promising components for next-generation electronic devices because of the diversity in their design. In the past two decades, nitronyl nitroxides and its related radicals were widely utilized for organic spin sources mainly because of their stability. These derivatives were generally prepared by the condensation reactions of a corresponding bis-hydroxylamine compound with various aldehydes followed by oxidation. However, the procedure was unsuccessful sometimes particularly when highly electron-donating or electron-accepting aromatic aldehydes were used. One of the key approaches for solving this problem is to develop metal-introduced nitronyl nitroxide at the C2 position: This radical-metal complex can be used as a stable equivalent of the C2-H deprotonated anion of the parent nitronyl nitroxide and can be applied to the cross-coupling reagent to introduce the nitronyl nitroxide skeleton in the reaction with aryl halides. We have also found that the developed radical-metal complexes have metal-dependent low oxidation potentials and one of them can be converted to a new iminonitroxide-Au trimer complex with a quartet ground state. Here, we report recent progress of synthetic methods of new functional nitronyl nitroxides as “π-system figuration for open-shell molecules” and their unique electrochemical and magnetic properties.

Organocatalyst realizes high yield and high selectivity by using non-covalent bond interactions. In these interactions, anion-π interaction which works between π-acidic surfaces and anions has been conducted to organocatalyst recently since a first report by Matile in 2013. Here, the recent development of anion-π catalysis is introduced from the viewpoints of stabilization mechanism of anionic transition states.