| Abstract: | Contributions to the Chemistry of Phosphorus. 106. Synthesis and Properties of the Diphosphacyclopropane (t-BuP)2CHMe The new 1,2-di-tert-butyl-3-methyl-1,2-diphosphacyclopropane (1,2-di-tert-butyl-3-methyl-diphosphirane), (t-BuP)2CHMe ( 1 ), is obtained by reacting K(t-Bu)P? P(t-Bu)K with 1,1-dichloroethane under suitable conditions. 1 can be isolated by high vacuum distillation and is stable for months when stored under inert gas at room temperature. Particularly, no dimerization to the corresponding 1,2,4,5-tetraphosphacyclohexane takes place. The NMR parameters indicate an increase of the exocyclic bond angles compared to (t-BuP)2CH2. The signs of all CP coupling constants have been determined by spin tickling experiments. The 2J(CCP)-coupling of the methyl group at the ring carbon depends strongly on the dihedral angle. |
