ω-3 Fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) produces hydroxylated metabolites that mediate resolution of inflammation process. Such metabolites are divided to E-series and D-series resolvins, protectins, and maresins. In addition to the hydroxyl groups, these metabolites involve conjugated diene, triene, and/or tetraene possessing one cis olefin. These conjugated olefins with hydroxyl groups are chemically unstable, so that usable reactions/reagents are limited at the last stage of the synthesis. This review summarizes synthesis of resolvins E1, E2, D5, protectin D1, and maresin 1, focusing on the methods that construct stereoselectively the conjugated olefins and alcoholic carbons of these metabolites.

Phthalocyanine is a fascinating conjugated molecule owing to the unique optical and electrochemical properties arising from the 18π-electron conjugated system, and it has been utilized in a variety of fields related to our daily life. Creation of novel functional molecules based on the structural modification of this molecule have, therefore, been of great importance. In the last decade, we have developed the synthesis of phthalocyanine analogues by core-modification as well as peripheral modification and revealed their unique optical and electrochemical properties. In addition, based on the knowledge obtained during the phthalocyanine research, we have developed a novel Schiff-base forming reaction, which provided a variety of aza-BODIPY analogues with unique absorption and emission in the visible and near infrared region. Application studies using these functional molecules as an organic photovoltaic material have also been conducted. In this account, the synthesis and structure-property relationship of these novel phthalocyanine-based functional molecules are described.

Several kinds of new reagents and methods for alkylation of organic compounds, particularly alcohols, have been developed by taking advantage of the π-electron deficient properties of 1,3,5-triazine. Based on the concept that 2,4,6-trialkoxy-1,3,5-triazine (TriAT) can be considered as the formal trimeric structure of the minimum units of an alkyl imidate, it was successfully demonstrated that TriATs act as acid-catalyzed O-alkylating reagents. N,N’-Dimethylated 6-(benzyloxy)-1,3,5-triazine-2,4(1H,3H)-dione (DMBOT) designed by alteration of the core structure of 2,4,6-tris(benzyloxy)-1,3,5-triazine (TriBOT) was found to show a superior reactivity in O-benzylation of alcohols; the reaction proceeds with a relatively mild pyridinium triflate as an acid catalyst. A trialkyltriazinylammonium salt, already activated by itself, spontaneously undergoes alkylation by dissolving it in an organic solvent including a nucleophile. Because all the compounds can be prepared from inexpensive cyanuric chloride within a few steps, they should be practically useful with respect to cost as well as their reactivities.

Our syntheses of fawcettimine-type Lycopodium alkaloids, hupezine Q, lycoposerramine-S and lycopalhine A are described. Huperzine Q was synthesized via a Diels-Alder reaction and a ring contraction reaction of an epoxyketone into a cyclopentanone. The synthesis of lycoposerramine-S features an intramolecular cycloaddition of azomethine ylide. The core structure of lycopalhine A was constructed by means of cleavage of a cyclopropane ring and intramolecular Michael addition of a sulfonamide moiety to an enone. Stereoselective introduction of the units to the core structure and formation of the ring systems led to the total synthesis of lycopalhine A.

Molecular crystalline materials that comprise π-electron organic molecules exhibit various interesting physical properties and functionalities related to electrical conductivity and magnetic, dielectric, and optical properties. Their experimental and theoretical studies have extensively been performed by a wide range of researchers in the fields of organic chemistry, physical chemistry, solid-state physics, and so on. In particular, synthetic organic chemists have devoted continuous effort to the design and synthesis of new functional molecular crystals and component molecules, which led to numerous important discoveries in this interdisciplinary research field. Here we report the development of a new type of organic conductors based on catechol-fused tetrathiafulvalene (TTF) derivatives. Interestingly, dynamic properties of hydrogen bonds through the catechol moiety are coupled with π-electrons on the TTF skeleton, which allowed us to discover unprecedented phase transitions, physical properties, and functionalities. In this paper, the design, synthesis, structures, and properties of our new molecules and crystals are described from a molecular point of view.

The cleavage of the C-N bond of aminals by a palladium complex was found to afford aminomethylpalladium complexes. Based on this elemental step, various aminomethylation reactions of unsaturated substrates were developed.