74641-61-5Relevant academic research and scientific papers
On the Problem of Regioselectivity in the 1,3-Dipolar Cycloaddition Reaction of Munchnones and Sydnones with Acetylenic Dipolarophiles
Padwa, Albert,Burgess, Edward M.,Gingrich, Henry L.,Roush, David M.
, p. 786 - 791 (2007/10/02)
The 1,3-dipolar cycloaddition reaction of several unsymmetrically substituted munchnones and sydnones with methyl propiolate has been examined.The initially formed cycloadducts readily extrude carbon dioxide to produce five-membered heteroaromatic ring compounds.The reaction of sydnones with methyl propiolate produced a mixture of regioisomeric pyrazoles.The analogous cycloaddition reaction of munchnones with methyl propiolate proceeds with formation of mixtures of both possible regioisomeric pyrroles.The structural assignment of the isolated adducts is based on spectroscopic data.The distribution of products depends on the nature and location of the substituent groups present on the heterocyclic ring.The observed regioselectivity is discussed on the basis of MO-perturbation theory.
PHOTOREAKTIONEN DES 3-METHYL-4-PHENYLSYDNONS
Pfoertner, Karl-Heinz,Foricher, Joseph
, p. 653 - 657 (2007/10/02)
A procedure for the synthesis of 3-methyl-4-phenylsydnone (1) is given.UV. irradiation of 1 in solution generates the nitrile-imine 4 which reacts with activated C,C double bonds and with heterocumulenes to give five-membered heterocycles.In contrast to the 2H-azirines which photochemically react with the C,O double bond of phenylisocyanate, 4 adds to the C,N double bond of the latter.
