Coenzyme-inspired chemistry 1: the C-2 alkylation of 4,5-dihydroimidazoles

Alkylation of 4,5-dihydroimidazoles at C-2 is accomplished using a double umpolung of the reactivity of that position, via sulfenylation of a nucleophilic C-2 lithio-species and substitution using an alkyl nucleophile. Arylation via unexpected sulfide contraction from the arylsulfenylation products has also been demonstrated. Taken with dihydroimidazole cleavage protocols, this constitutes a tetrahydrofolate-inspired C1-transfer protocol.