A NEW METHOD FOR MIXED HALOGENATION. N-CHLOROAMINE-PHOSPHORUS BROMIDE SYSTEM AS A SYNTHETIC EQUIVALENT OF THE MIXED HALOGEN Cl<sup>+</sup>Br<sup>−</sup>
作者:Nikolai V. Zyk、Elena K. Beloglazkina、Vladimir S. Tyurin、Nikolai S. Zefirov
DOI:10.1080/10426509808035682
日期:1998.8.1
A new method for the mixed halogenation of alkenes has been proposed based on the reaction of olefins with N-chloroamines in the presence of phosphorus bromide or oxybromide. The plausible reaction mechanism and the results of reactions with a number of model unsaturated compounds such as cyclohexene, 1-heptene. ethyl cinnamate, norbornene and those from the bicyclo[2.2.1]heptane series are discussed. In the reactions with reactive olefins this reagent acts as a synthetic equivalent of the unknown mixed halogen [Cl+Br-] with "abnormal" polarity of halogen atoms. The same reactions activated by PCl3 or POCl3 result in dichlorides in yields near to quantitative.