Dehydration Triphenylphosphine-Diethyl azodicarboxylate

Isocyanides. Ugi et at.3 investigated the synthesis of isocyanides (2) by dehydration of N-monosubstituted formamides (1) with triphenylphosphine-diethyl azodicarboxylate. In the 11 cases investigated, no isocyanide could be obtained in six of them. In the... 

O-protective groups such as 11 has been successfully achieved without affecting these groups by dehydration with triphenylphosphine-diethyl azodicarboxylate-iodine a mixture of anomeric C-nucleosides (12) was usually produced [94CL265 95JAP(K)95/118268] (Scheme 4). 

One of the most widely used procedures for dehydrative coupling and cyclization reactions is the Mitsunobu reaction in which the components are treated with triphenylphosphine and diethyl azodicarboxylate (DEAD, EtOaC—N=N—COiEt). The overall equation for reaction of an alcohol 67 with an acid 68 to form the ester 69 is as shown and the active species is the zwitterionic... 

Grochowski, E., Hilton, B. D., Kupper, R. J., Michejda, C. J. Mechanism of the triphenylphosphine and diethyl azodicarboxylate induced dehydration reactions (Mitsunobu reaction). The central role of pentavalent phosphorus intermediates. J. Am. Chem. Soc. 1982,104, 6876-6877. 

There are efficient ways in which to use starting materials that have the carboxylic acid component already installed on both heteroatoms conversion to bis(silyloxy) derivatives, or simply heating with p-toluenesulfonic acid. An excellent route to mono-acylated precursors utilises mixed anhydrides. A very mild method for the dehydrative ring closure of ortfto-hydroxyarylamino-amides utilises typical Mitsunobu conditions - triphenylphosphine and diethyl azodicarboxylate. ... 

Inter and intramolecular nucleophilic displacement of alcohols with inversion by means of diethyl azodicarboxylate (DEAD)-triphenylphosphine and a nucleophile. Also dehydration, esterification of alcohols or alkylation of phenols and one step synthesis of nitriles from alcohols (see 1 st edition). 

Oxepan and other oxygen- or nitrogen-containing saturated heterocycles can be prepared in high yield by the dehydrative coupling of aamino-alcohols, using diethyl azodicarboxylate and triphenylphosphine. The synthetically useful oxepin-2,7-diones (muconic acid anhydrides) can be conveniently prepared by the oxidation of ortho-henzoquinones with w-chloroperoxybenzoic acid. °... 

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