Reactivity of dimethylphenylsilyllithium toward 5- and 6-substituted 1,3-dimethyluracil derivatives

Article abstract of DOI:10.3987/COM-98-8270

Dimethylphenylsilyllithium (PhMe₂SiLi) reacts with 5-substituted 1,3-dimethyluracils by selective addition at the electrophilic C-6 position of the uracil ring to give the corresponding 6-dimethylphenylsilyl-5,6-dihydrouracil derivatives. The reaction of PhMe₂SiLi with 6-substituted 1,3-dimethyluracils showed a different selectivity, and an unusual addition at the C-5 position was observed. This synthetic procedure appears to be an efficient entry to a new class of highly functionalized 5,6-dihydro-1,3-dimethyluraciIs characterized by the presence of a silicon substituent selectively introduced at the C-5 and C-6 positions of the uracil ring.