Mitsunobu Reaction

In 1967, O. Mitsunobu demonstrated the acylation of secondary alcohols with carboxylic acids in the presence of diethyl azodicarboxylate (DEAD) and triphenylphosphine. Later it was discovered that optically active secondary alcohols underwent total inversion of configuration under these reaction conditions, and this procedure was found to be general for the synthesis of optically active amines, azides, ethers, thioethers, and alkanes. Since then, the substitution of primary and secondary alcohols with nucleophiles in the presence of a dialkylazodicarboxylate and a trialkyl- or triarylphosphine has become known as the Mitsunobu reaction.

An important development of this reaction was made by T. Mukaiyama, who prepared inverted tert-alkyl carboxylates from chiral tertiary alcohols via alkoxydiphenylphosphines formed in situ from 2,6-dimethyl-1,4-benzoquinone.

The synthesis of the potent antitumor antibiotic (+)-duocarmycin A utilized the Mitsunobu reaction during the final stage, a special case where the reaction is used to create new carbon-carbon bonds.