Regioselective 1,3-dipolar cycloaddition of phenanthrolinium N-ylides to substituted arylidene oxazolones

Abstract

The 1,3-dipolar cycloaddition reactions of phenanthrolinium ylides have been investigated. Thus 15 novel aryl substituted spiro[oxazole-4,10'-pyrrolo[1,2-a][1,10] phenanthrolin]-5-ones were prepared in a regioselective manner, by the treatment of phenanthrolinium ylides with (Z)-arylidene oxazolones.

Synthesis of Spiro[imidazole‐4,3′‐pyrrolo[1,2‐a]quinolin]‐ 5‐ones via 1,3‐Dipolar Cycloaddition of Quinolinium Ylides with Arylydeneimidazol‐4‐ones

“…However, nearly the same coupling constant (9.7 Hz) and the same NOE interaction suggest, that it is epimer of major derivative 3 fa at spirostereocenter (analogously as it was observed earlier in the related work on phenanthroline ylides. [28] The stereochemical outcome of the reaction could be rationalized, based on the previously established mechanism of the related cycloaddition (Scheme 5). [19] Quinoline ylides may exist in two conformations: "transoid" and "cisoid", each of them provide two possible approaches of arylideneimidazol-4-one 1 ("exo" and "endo"), which may produce up to four diastereomers.…”

“…Highly stabilized ylides, derived from heteroaromatic compounds, were intensively studied in the 70–80s, but due to low stability of their cycloadducts and total reversibility of the reaction, they did not get in further application (Scheme 1, a ) [18–21] . Only recently, after seminal works [22,23] on the in situ elaboration of the cycloadducts into bioactive aromatized or rearranged products, the research interest into reactions of aromatic azomethine ylides have revived [24–34] …”

Novel sydnone derivatives carrying azidomethyl-1,2, 4-oxadiazole unit and their 1,3-dipolar cycloadditions

“…Taking account of the above considerations together with our continuing interest in the 1,3-dipolar cycloaddition chemistry of various ylides leading to triazoles and spiropyrroles, [18][19][20][21] we focus herein on the synthesis of oxadiazolyl-substituted sydnones starting from sydnones and their carboxamidoxime derivatives which were subsequently converted into azidomethyl compounds. The latter were engaged in a series of representative electron-deficient alkenes and alkynes, and their cycloaddition reactions.…”

Synthesis of novel triazoles bearing 1,2,4-oxadiazole and phenylsulfonyl groups by 1,3-dipolar cycloaddition of some organic azides and their biological activities

“…31−39 * Correspondence: yasardurust@ibu.edu.tr Sulfones are known as an important class of compounds and various sulfone containing heterocycles have been shown to possess diversified bioactivities such as antibacterial, antimalarial, anthelmintic, antilepral, antineoplastic, antiinflammatory, and antidiabetic activities. 40 In reference to the reasons mentioned above and our ongoing interest in 1,3-dipolar cycloaddition reactions of the various types of ylides, 41 1,2,4-oxadiazolyl substituted azides, 42 and phenyl vinyl sulfone, 43 and due to very infrequent studies on the cycloaddition reactions between organic azides with dipolarophiles such as phenyl vinyl sulfone and bismaleimide, we have focused on the synthesis of a series of pyrrolotriazole derivatives carrying 1,2,4-oxadiazole and phenylsulfonyl groups and their biological activities.…”