| Abstract: | Contributions to the Chemistry of Phosphorus. 128. Synthesis of the Diphosphastanna-cyclopropane (t-BuP)2Sn(t-Bu)2 The first three-membered P2Sn heterocycle, 1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastanna-cyclopropane (1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastannirane) ( 1 ), has been synthesized by 2+1] cyclocondensation of K(t-Bu)P—P(t-Bu)K with (t-Bu)2SnCl2. 1 is stable at room temperature. Besides, (t-BuP)2Sn(t-Bu)2]2 ( 2 ), (t-BuP)4Sn(t-Bu)2 ( 3 ), and (t-BuP)4 are formed. In the reaction with Et2SnCl2, the six-membered ring compound (t-BuP)2SnEt2]2 ( 4 ) is the main-product; the four- and five-membered cyclostannaphosphanes (t-BuP)3SnEt2 ( 5 ) and (t-BuP)3(SnEt2)2 ( 6 ) are also formed. 1 could be isolated in the pure state and has been unambiguously characterized as a three-membered heterocycle with a P2Sn skeleton. The 31P-NMR parameters of the other new cyclostannaphosphanes 2–6 are reported. |
