Our recent study on metallation of isocyanides and its synthetic application has been reviewed. Metallation of isocyanides is achieved by an insertion of isocyanides into metal-metal or metal-carbon linkage of a variety of organometallic compounds giving the corresponding N-substituted (α-iminoalkyl) metal compounds. The reaction of N-substituted (α-iminoalkyl) metal compounds thus formed with electrophiles affords the coupled imino compounds, which are transformed to the corresponding ketones by hydrolysis of the imino group. Therefore, N-substituted (α-iminoalkyl) metal compounds act as acylation equivalents, which permit nucleophilic introduction of the acyl group into organic molecules. A new living polymerization of 1, 2-diisocyanoarenes giving poly (2, 3-quinoxaline) on the basis of the multiple successive insertion of isocyanides is also described.
Current research and development trends in manufacturing technology for aromatic aldehydes are reviewed including oxidation, halogenation, formylation and reduction methods. In addition to the subject, a new technology of direct hydrogenation reaction of carboxylic acids with molecular hydrogen, which is commercialized recently using authors' catalyst, is briefly summarized.
Synthetic methods, factors which influence the stability, and various reactions of 1-hydroxyindoles and their derivatives are reviewed.Total syntheses of natural products having 1-methoxyindole nucleus are also discussed. Some hypotheses for the presence and the role of 1-hydroxyindoles in a living body are proposed.
Regioselective addition reaction of epoxy compounds with esters was investigated using low molecular weight tert-amines, quaternary onium salts, complexes of crown ethers-metal salts, or insolublized poly (styrene) beads containing pendant amine, quaternary onium salt, or crown ether moieties, as catalysts. Although the reaction proceeded smoothly under relatively mild reaction conditions to give the corresponding adducts with high yields, the rate of addition reaction and the yield of product were strongly affected by the kind of catalyst. Poly-addition reaction of di-epoxy compounds with di-esters proceeded to give the corresponding polyesters in the presence of various quaternary onium salts. Addition reaction of poly (glycidyl methacrylate) (PGMA) with some esters such as S-phenylthio benzoate and p-nitorophenyl cinnamate proceeded with high efficiency to give the corresponding polymers. Insertion reaction of epoxy compounds into phenyl ester linkage of polymer chains was also achieved using those catalysts. Thermal crosslinking reaction of epoxy resins using poly-functional phenyl esters or thioesters proceeded to give gel products as well as the reaction of PGMA with poly-functional esters or the reaction of poly (phenyl methacrylate) s with poly-functional epoxy compounds using quaternary onium salts or crown ether complexes.