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The reaction mechanism of the Mitsunobu reaction is fairly complex. The identity of intermediates and the roles they play has been the subject of debate. Initially, the triphenyl phosphine (2) makes a nucleophilic attack upon diethyl azodicarboxylate (1) producing a betaine intermediate 3, which deprotonates the carboxylic acid (4) to form the ion pair 5.
Reactions normally result in the inversion of molecular symmetry. DEAD was used in the original 1967 article by Oyo Mitsunobu, [14] and his 1981 review on the use of diethyl azodicarboxylate is a top-cited chemistry article. [15] [16] The Mitsunobu reaction has several applications in the synthesis of natural products and pharmaceuticals.
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C 6 H 5) 3 and often abbreviated to P Ph 3 or Ph 3 P. It is versatile compound that is widely used as a reagent in organic synthesis and as a ligand for transition metal complexes, including ones that serve as catalysts in organometallic ...
Phosphate ester are synthesized by alcoholysis of phosphorus oxychloride. A variety of mixed amido-alkoxo derivatives are known, one medically significant example being the anti-cancer drug cyclophosphamide. Also derivatives containing the thiophosphoryl group (P=S) include the pesticide malathion.
Diisopropyl azodicarboxylate (DIAD) is the diisopropyl ester of azodicarboxylic acid. It is used as a reagent in the production of many organic compounds. It is often used with triphenylphosphine in the Mitsunobu reaction, [2] wherein it serves as a hydride acceptor. It has also been used to generate aza-Baylis-Hillman adducts with acrylates. [3]
One of the first applications of phosphine ligands in catalysis was the use of triphenylphosphine in "Reppe" chemistry (1948), which included reactions of alkynes, carbon monoxide, and alcohols. [16] In his studies, Reppe discovered that this reaction more efficiently produced acrylic esters using NiBr 2 (PPh 3) 2 as a catalyst instead of NiBr 2.
Reduction, iodination, and treatment with triphenylphosphine led to phosphonium salt. Figure 2. Fragments 1, 2, and 3 were reacted with each other to deliver epothilone B in an approach including Wittig reaction, aldol reaction, and Yamaguchi esterification (Figure 3).
Reactions. Triphenylphosphite is a precursor to trimethylphosphine, it serves as a source of P 3+ that is less electrophilic than phosphorus trichloride: [1]