BIS-AND TRIS-N-CYANO-AND N-SULFAMIDOPHOSPHA-Λ⁵-AZENES FROM A REDOX-CONDENSATION REACTION AND THE NOVEL REACTION OF SULFAMIDE WITH BIS(DIPHENYLPHOSPHINO)METHANE

Abstract

Cyanamide (3) has been shown to react with 1,2-bis(diphenylphosphino)ethane (8), 1,3-bis(diphenylphosphino)propane (9) and bis(2-diphenylphosphinoethyl)phenylphosphine (10) in the presence of diethyl azodicarboxylate (DAD) to produce, in good yields, the corresponding bis-and tris-N-cyanophospha-Λ⁵-azenes, 1,2-bis(N-cyanodiphenylphospha-Λ⁵-azeno)ethane (11), 1,3-bis(N-cyanodiphenylphospha-Λ⁵-azeno)propane (12) and N-cyano-bis[2-(N-cyanodiphenylphospha-Λ⁵-azeno)ethyl]phenylphospha-Λ⁵-azene (13) respectively. Sulfamide (6) has been shown to react with bis(diphenylphosphino)methane (1) and DAD to give [(N-sulfamidodiphenylphospha-Λ⁵-azeno)methyl]diphenylphosphine oxide (14) in 69% yield and the cyclic system, 3,3,5,5-tetraphenyl-4H-1,2,6,3Λ⁵,5Λ⁵-thiadiazadiphosphorin-1,1-dioxide (7), in 6% yield. It is postulated that there is a special, as yet unidentified, intramolecular effect which is operative in producing 14 and is most likely sterically related to the intramolecular effect we recently observed in the reaction of 1 with urea and DAD, which produced an anomalous product. The isolation of the cyclic molecule 7 is the first time a ring system has been observed in the oxidation-reduction condensation system involving a bisphosphine, bis-amide and DAD. Reaction of bis-and tris-phosphines 8, 9 and 10 with sulfamide (6) and DAD produce, again in good yields, the phospha-Λ⁵-azenes, 1,2-(bis-N-sulfamidodi-phenylphospha-Λ⁵-azeno)ethane (18), 1,3-(bis-N-sulfamidodiphenylphospha-Λ⁵-azeno)propane (19) and N-sulfamido-bis[2-(N-sulfamidodiphenylphospha-Λ⁵-azeno)ethyl]phenylphospha-Λ⁵-azene (20), respectively.

Key Words:

• N-cyanophospha-Λ⁵-azenes
• N-sulfamidophospha-Λ⁵-azenes
• cyclic bis-phospha-Λ⁵-azene
• mono-N-sulfamidophospha-Λ⁵-azene-mono-phosphine oxide