Charge-transfer Intermediate in The Reaction of Thioketone with Nucleophiles

Thiobenzophenone reacts with butyllithium, phenyllithium, and sodium ethoxide in ethanol giving benzhydryl butyl sulfide, benzhydryl phenyl sulfide, and dibenzhydryl disulfide, respectively. On the other hand di-t-butyl thioketone affords 2,2,4,4-tetramethylpentane-3-thiol, 2,2,4,4-tetramethyl-3-phenylpentane-3-thiol, and 2,2,4,4-tetramethylpentane-3-thiol by the reaction with butyllithium, phenyllithium, and sodium ethoxide in ethanol, respectively. Product analyses and tracer experiments with deuteriums have revealed that these reactions proceed through a charge-transfer mechanism.