Development of A New Cycloaddition Reaction Involving Azatrimethylenemethane Metal Complexes

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Transition-metal catalyzed reactions involving azatrimethylenemethane (ATMM) -palladium were investigated in detail, and structures of some ATMM-palladium and -platinum complexes were fully characterized. We demonstrated the utility of 4-methyleneoxazolidin-2-one (1) as a precursor of ATMM.The palladium-catalyzed reaction of 4-methylene-3-tosyloxazolidin-2-one (1a) with norbornenes exclusively gave a cyclopropanation product, while the reaction of 4-methylene-3-aryloxazilidin-2-one (1f-1) mainly produced a cyclopentaannulation product. The intermediacy of an ATMM-palladium, [CH_2C (NR) CH_2] PdL_2 was elucidated by the stoichiometric and catalytic reactions employing the isolated complex. The results shows that the isomerization of an intermediate during the catalytic process leads to the formation of the cyclopropanes. All spectral data of ATMM-metal complexes indicated that the palladium complexes have the nature close to eta^3-mode and the corresponding platinums to eta^2-mode. Variable temperature NMR studies on the ATMM-platinum complexe exhibited the dynamic ring-puckering with eta^2-coordination mode in a solution. The solid-state structures of [CH_2C (NTs) CH_2] Pt (PPh_3) _2 was confirmed by an X-ray crystallography. Crystal data for [CH_2C (NTs) CH_2] Pt (PPh_3) _2 at 25ﾟC : C_<46>H_<41>NO_2P_2SPt, triclinic, a=15.635 (4) *, b=17.525 (5) *, c=11.126 (4) *, alpha=104.06 (3) ﾟ,beta=109.28 (2) ﾟ,gamma=66.56ﾟ,P_1, Z=2.