Development of New Versatile Reagents for Mitsunobu Reaction. -Utilization of Wittig Reagent as a New Mitsunobu Reagent-

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The Mitsunobu reaction, a popular alkylation reaction utilizing the redox system between diethyl azodicarboxylate and triphenylphosphine, has a shortcoming that it can only be applied satisfactorily to a nucleophile (HA) of pK_u less than 11. In order to overcome the limitation, we introduced several combinations of azodicarboxamides (TIPA, ADDP, TMAD, and DHTD) and tributylphosphine. In our continual search for new versatile reagents, we found cyanomethylenetrialkylphosphorane (CMBP, CMMP) was capable of mediating the alkylation of various HA of larger pK_u than 11. Utilizing these reagents, the efficient alkylation of N-, C-, and O-nucleophiles, such as tosylamides, active methylene compounds, alcohols, and carboxylic acid was accomplished. The reaction was applied for the synthesis of biologically active compounds.