作者:Jacek E. Nycz
DOI:10.1080/10426500802531677
日期:2009.10.13
The present study shows new aspects of the synthesis of polyhalogenoarylphosphanes. The sterically hindered anions Ph(R)P-Y(-) (1a-c, Y = O, lone pair; R = Ph, Bu(t)) have been used to show the complexity of the reaction between phosphorus nucleophiles and hexahalogenobenzenes or 9-bromofluorene (E3). The Ph(Bu(t))P-O(-)(1a) anion reacts with hexachlorobenzene (E1), hexafluorobenzene (E2), or E3 to give Ph(R)P(O)X (4a-c, X = F, Cl, Br) with the release of the corresponding carbanion as a nucleofuge, followed by side reactions. In contrast, the lithium phosphides Ph(R)PLi (1b, c) react with hexahalogenobenzenes to give the corresponding diphosphanes 5a,b as the main product and traces of P-arylated products, i.e., Ph(R)P-C(6)X(5) (10a,b, X = Cl, F). Unexpectedly, Ph(Bu(t))PLi (1b) reacts with an excess of 9-bromofluorene to give only halogenophosphane Ph(Bu(t))P-X.