New Phosphorus Heterocycles by Rearrangement of a [1,4‐Bis(trimethylsilyl) η8‐cyclooctatetraene‐1,3,5‐triphospha‐7‐hafnanorbornadiene Complex

Abstract

Abstract[1,4‐Bis(trimethylsilyl)‐n8‐cyclooctatetraene]‐2, 4, 6‐tri‐tert‐butyl‐1, 3, 5‐triphospha‐7‐hafnanorbornadiene (3) rearranges nearly quantitatively to the corresponding 3,5,6‐tri‐tert‐butyl‐1,2,4‐triphospha‐7‐hafnanorbornadiene complex 5 upon heating at 70°C. Treatment of complex 5 with trimethylphosphane at 50°C induces the displacement of di‐tert‐butylacetylene to give the new (n4‐triphosphacyclobutadiene)hafnium complex 7, the crystalstructure of which has been determined by X‐ray analysis. From complex 5 3,5,6,‐tri‐tert‐butyl‐1,2,4‐triphospha Dewar benzene (6) can be synthesized by a redox reaction with hexachloroethane.