2,6-Dimethoxyphenylphosphirane is readily converted to its oxide and sulfide whose pyrolysis and (perhaps) photolysis lead to the generation of phosphinidene chalcogenides Ar-P=Z (Z=O,S). Trapping experiments were carried out under conditions similar to the kinetic studies of the phosphirane chalcogenide pyrolyses that confirmed the formation of free Ar-P=Z. The trapping experiments were in accord with carbene-like character for Ar-P=Z, and the activation parameters suggest a non-least motion pathway for the addition of Ar-P=Z to olefins. This represents quantitative evidence for the validity of the predictions of frontier-orbital theory for species that undergo reactions with small (or no) enthalpic barriers.
Bibliographical noteFunding Information:
This work has received financial support from National Science Foundation Grant CHE-9632897. NMR instrumentation was made available in part through NIH Shared Instrument Grants RR-02004, RR-05018 and RR-07155. Dr Frank Borkenhagen provided valuable experimental advice.
Copyright 2004 Elsevier Science B.V., Amsterdam. All rights reserved.
- Phosphine oxides
- Phosphine sulfides
- Phosphorus heterocycles
- Strained compounds