ISSN:
0947-6539
Keywords:
heterocycles
;
organic syntheses
;
phospholes
;
phosphorus ylides
;
ring expansions
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Condensation of a 1,3-diphosphoniopropenide cation at its reactive 1,3-positions with a dichlorophosphine in the presence of triethylamine provides a route to 2,4-diphosphoniodihydrophosphetide cations. An excess of dichlorophosphine in the presence of an additional reducing agent results in a ring expansion and yields 3,5-diphosphoniodihydro-1,2-diphospholide cations. The chlorosubstituted cation derived from PCl3 can be further reduced to the hydrolytically stable 3,5-diphosphonio-1,2-diphospholide cation. It adds halogen to the P=P bond and can easily be regained from the halogen adduct. Structural comparison of the 1,2-diphenyl- and 1,2-dichlorodihydro-1,2-diphospholide cation with the 1,2-diphospholide cation shows three stages of interaction of the C3 and the P2 entities of the ring: no conjugation in the first case, hyperconjugative extension of the allylic system to include the phosphorus atoms in the second case and cyclic π conjugation in the third.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19960020215
