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Asymmetric aza-Henry reaction of cyclic ketimines, which are easily prepared by the oxidation of commercially available cyclic amino acids with nitroalkanes was accomplished by using our original cinchona alkaloid sulfonamide/zinc(ii) catalyst.

This paper provides the first report of the intramolecular [2+2] cycloaddition of vinylsilane. The [2+2] cycloaddition of allenes is a useful reaction that can synthesize cyclobutanes. However, no previous works have attempted to control the regioselectivity between the two double bonds of allenes only by changing the reaction conditions, although there have been some reports of the regioselective [2+2] cycloaddition of allenes by changing the substrate. In this study, we have succeeded in controlling intramolecular [2+2] cycloaddition reactions at the proximal and distal positions of allenes simply by changing the reaction conditions. We found that the atomic radius of silicon is very important for perfect control of the reaction's sites. The structures of all key compounds were determined by the crystal sponge method which could identify the structures of liquid compounds.

We have developed a continuous microwave irradiation-assisted Buchwald–Hartwig amination using our original Pd nanoparticle catalyst with a copper plate as a co-existing metal solid. In this methodology, a microwave-controlled product selectivity was achieved between Buchwald–Hartwig amination and aryne amination performed under strongly basic conditions and at a high reaction temperature, because a polar chemical species such as Ar–Pd–halogen might be activated selectively by microwave radiation. Moreover, our catalyst could be used repeatedly over 10 times, and the amount of Pd leaching could be suppressed to a low level.

Two 1-[6]helicenol derivatives were synthesized by Ni-catalyzed [2+2+2] cycloaddition on a multigram scale. Both enantiomers of the 1-[6]helicenols could be efficiently prepared by simple optical resolution. As a synthetic application of helically chiral 1-[6]helicenols, a novel class of [6]helicene-based phosphinites was developed; these compounds represent the first examples of helically chiral phosphinite ligands. Up to 90 % ee was obtained for the Pd-catalyzed asymmetric allylic alkylation reaction.

The one-pot reactions of catalytically generated bicyclic zinc enolate with various electrophiles are reported. The zinc enolate as a key intermediate is efficiently delivered from Ni-catalyzed reductive cyclization of alkynyl cyclohexadienone. Employing aldehydes, imine, nitroalkene, and α,β-unsaturated carbonyl compounds as electrophiles, this new class of one-pot reactions gave multi-functionalized cis-hydrobenzofurans and octahydro-4,7-ethanobenzofuran-9-one derivatives in moderate to good yields.