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Abstract: The catalytic trifluoromethylation of uracil using CF3I was investigated to find a new industrial process for the production of 5-trifluoromethyluracil. The catalytic system of FeSO4, H2O2 and H2SO4 in dimethylsulfoxide efficiently and selectively yielded 5-trifluoromethyluracil under mild conditions. FeSO4 exhibited the highest activity among the Fe(II) compounds tested. H2O2 was indispensable for the reaction and only Fe(II) compounds yielded the desired product. This characteristic of the reaction suggests that it proceeds in a Fenton oxidation manner. The reaction was applicable to large-scale production: 50kg of 5-trifluoromethyluracil in a 600L reactor. By the use of this catalytic system, selective trifluoromethylation at the 5-position was also performed with various uracil derivatives including uridines. Interestingly, Cp2Fe was superior to FeSO4 for several substrates. [Copyright &y& Elsevier]

Chiral P-spiro triaminoiminophosphorane (1) was developed to promote the highly regio-, diastereo-, and enantioselective 1,6- and 1,8-additions of azlactones (2·H) to dienyl and trienyl N-acylpyrroles (3 and 4). DFT calculations enabled us to gain deep insight into the whole reaction mechanism as well as the origin of the high regio- and stereoselectivities. The present reaction consists of three steps: (1) formation of the phosphonium-enolate ion-pair complex by deprotonation of 2·H with 1, (2) C-C bond formation of 2 with 3 and 4, and (3) protonation of the resulting enolate anion. The C-C bond formation is irreversible, and the rate- and stereodetermining step. The C α -protonation preferentially proceeds rather than the thermodynamically and kinetically disfavored O- and C γ -protonation, respectively. The high regio- and enantioselectivities are mainly attributed to the steric and electronic features of 1·H and 3/4. The hydrogen bonds (NH-O and CH-O) and the attractive CH-π interaction between 1·H and 2 and 3 play a key role in achieving high stereocontrol. The high regioselectivity is mainly controlled by the structural distortion of 1·H and the disruption of the π-conjugated system of 3 (1,4-system) and 4 (1,4- and 1,6-systems).