Unusual products in the reactions of phosphorus(III) compounds with N=N, C=C or conjugated double-bonded systems

Abstract

The diversity of products in the reaction of diethyl azodicarboxylate (DEAD)/diisopropyl azodicarboxylate (DIAD) and activated acetylenes with P III compounds bearing oxygen or nitrogen substituents is discussed. New findings that are useful in understanding the nature of intermediates involved in the Mitsunobu reaction are highlighted. X-ray structures of two new compounds (2-t-Bu-4-MeC6H3O)P (μ-N-t-Bu) 2P+[(NH-t-Bu){N[(CO2-i-Pr)(HNCO 2-i-Pr)]}](Cl-(2-t-Bu-4-MeC6H3OH) (23) and [CH2(6-t-Bu-4-Me-C6H2O) 2P(O)C(CO2Me)C-(CO2Me)CClNC(O)Cl] (33) are also reported. The structure of 23 is close to one of the intermediates proposed in the Mitsunobu reaction. © Indian Academy of Sciences.