Studies on the Preparation and Reactions of Tritylsuffenimines

Carbonyl compounds react with stable, crystalline triphenylmethanesulfenamide (TrSNH2, 4) under mild conditions to form tritylsulfenimines 5 and 6. Lithiation of acetone tritylsulfenimine (5c) at 0 °C led to a novel rearrangement-decomposition producing tritylacetone (8). Lithiated tritylsulfenimines were found to undergo temperature-dependent ambident alkylation reactions leading to carbon-alkylated products 9 at -78 °C and nitrogen-alkylated products 10 at -20 °C. Lithiated tritylsulfenimines 5 reacted with carbonyl compounds at -78 °C to form adducts 11 from which the sulfenimine could be hydrolytically cleaved under mild conditions (AgN03/H2O-THF), thus effecting “directed aldol” condensation. Tritylsulfenimines 5 and 6 were reduced with NaBHgCN under mildly acidic conditions to form stable triphenylmethanesulfenamides 13 and 14.