Beiträge zur Chemie des Phosphors, 124 Tri-tert-butyl-diphosphastiba-cyclopropan, (t-BuP)2Sb(t-Bu)/Contributions to the Chemistry of Phosphorus, 124 Tri-tert-butyl-diphosphastiba-cyclopropane, (t-BuP)2Sb(t-Bu)

Abstract

Abstract The first three-membered P2Sb heterocycle, tri-tert-butyl-diphosphastiba-cyclopropane (tri-tert-butyl-diphosphastibirane) (1) was synthesized by [2+1] cyclocondensation of K(t-Bu)P-P(t-Bu)K with t-BuSbCl2 in n-pentane at -78 °C. Tetra-tert-butyl-1,2-diphospha- 3,4-distiba-cyclobutane (2), tetra-tert-butyl-triphosphastibacyclobutane (3) as well as (t-BuP)4 and five-membered cyclostibaphosphanes are also formed. Because of its hyperreactivity, 1 could not be isolated in a pure state. It forms two diastereomers, of which the isomer with trans-oriented tert-butyl groups at the phosphorus atoms is the more stable one. The 31P NMR parameters of the four-membered cyclostibaphosphanes 2 and 3 are reported.