Minoru Ishikura

A synthetic use of the intramolecular alkyl migration process in indolylborates for intramolecular cyclization: a novel construction of carbazole derivatives

The intramolecular alkyl migration reaction in indolylborates was developed for the one-pot construction of carbazoles via intramolecular cyclization in which π-allylpalladium complexes were successfully adopted as an acceptor for the indole nucleophile.

First synthesis of 2′,3′-epimino-carbocyclic nucleosides

The preparation of 2,3-epimino-carbocyclic analogues of adenosine is reported. The reaction of p-tosyl azide with N-substituted 2-azabicyclo[2.2.1]hept-5-en-3-one (ABH) (1a) provided aziridine-fused ABH (2), which was converted to 2,3-epimino-carbocyclic nucleosides (11).

Investigation of the Ring-opening Cross-Metathesis Reaction of 2-Azabicyclo-[2.2.1]hept-5-en-3-one (ABH) with Allylsilanes

An examination of the ring-opening cross-metathesis reaction of N-substituted 2-azabicyclo[2.2.1]hept-5-en-3-ones (ABH) (1) with allylsilanes (2) in the presence of ruthenium catalysts was undertaken.

Ruthenium-catalyzed Ring-opening Cross-Metathesis Reaction of 2-Azabicyclo[2.2.1]hept-5-en-3-one

An examination of the ring-opening cross-metathesis reaction of 2-azabicyclo[2 2.1]hept-5-en-3-one (ABH) (la) with allyltrimethylsilane in the presence of Grubbs catalyst showed that a pair of regioisomeric products (2) (R=Boc) and (3) (R=Boc) could be isolated instead of the known regioselective formation of 2 (R=Boc).

Preparation of 2',3'-Epimino-carbocyclic Nucleosides Based on 2-Azabicyclo[2.2.1]hept-5-en-3-one

The thermal reaction of N-substituted 2-azabicyclo[2.2.1]hept-5-en-3-one (ABH) (1) with tosyl azide, which allowed the stereoselective introduction of an aziridine moiety into ABH (1), led to the facile construction of 6-azabicycln[3.1.0]hexane (3). Successful conversion of 3 to the hitherto unknown 2,3-epimino-carbocyclic nucleosides (8) could be attained through a series of steps.

A novel C–C bond formation reaction with 1-methoxymethylindolylborate

The reaction of 1-methoxymethylindolylborates 2 with electrophiles in the presence of benzaldehyde enabled the novel construction of tri-substituted indoles in a one-pot procedure.

Preparation of 2',3'-Methano-carbocyclic Nucleosides through the Addition of Diazomethane to 2-Azabicyclo[2.2.1]hept-5-en-3-one

The preparation of 2,3-methano-carbocyclic analogues of adenosine is reported. The addition of diazomethane to N-substituted 2-azabicylo[2.2.1]-hept-5-en-3-one (ABH) (1) provided cyclopropane-fused ABH (3), which was converted to 2,3-methano carbocyclic nucleosides (8).