109123-08-2Relevant academic research and scientific papers
Phosphorus Compounds with Unusual Coordination, 21. - Cycloaddition of Mesoionic Compounds onto a Stable Phosphaalkyne - New Facilities in the Synthesis of Aza- and Thiaphospholes
Roesch, Wolfgang,Richter, Hans,Regitz, Manfred
, p. 1809 - 1814 (2007/10/02)
1,2,3-Oxadiazolium-5-olates (sydnones) (2a-e) react with the phosphaalkyne 1 under cycloaddition and following cycloelimination of carbon dioxide to give 1H-1,2,4-diazaphospholes 5a-e.Only in the reaction 1 + 2a the regioisomer 6a can also be detected as by-product.Starting with 1H(or 2H)-1,2,4-diazaphospholes some representatives of the same series are accessible by lithiation and subsequent methylation (7a-c -> 8a-c -> 5a,c,e).The 1,3-oxazolium-5-olate (muenchnone) 12 as well as the 1,3-dithiolium-4-olate 14 react analogously with 1 to yield the 1,3-aza- and 1,3-thiaphosphole 13 and 15, respectively.Constitutional isomeric thiazaphospholes (17, 18) are formed in the reaction of 1 with the 1,2,3-oxathiazolium-5-olate 16.
