Reactivity of Mitsunobu reagent toward carbonyl compounds.

[reaction: see text] The nitrogen-based nucleophile generated from azodicarboxylate and triphenylphosphine displayed an excellent reactivity toward carbonyl compounds to generate a variety of different final products depending on the substituent pattern on the carbonyl carbon. From the structures of these adducts, a straightforward mechanistic interpretation for the formation of different products is provided.