87444-84-6Relevant academic research and scientific papers
HEXACARBONYLMOLYBDENIUM-INDUCED FORMATION OF PYRIDINES FROM ISOXAZOLES AND ACETYLENIC ESTER
Kobayashi, Tomoshige,Nitta, Makoto
, p. 1233 - 1236 (1983)
Upon treatment with Mo(CO)6 in anhydrous benzene, substituted isoxazoles undergo a novel inclusion of dimethyl acetylenedicarboxylate across the C4-C5 bond and loss of an oxygen atom to lead to pyridines.
Novel Conversion of Selenium-containing Five-membered Aromatics to Nitrogen-containing Six-membered Aromatics via Hetero Diels-Alder Reaction with Acetylenic Dienophiles
Takikawa, Yuji,Hikage, Shigeki,Matsuda, Youichi,Higashiyama, Kazuyuki,Takeishi, Yoshiyuki,Shimada, Kazuaki
, p. 2043 - 2046 (2007/10/02)
Treatment of selenium-containing five-membered heteroaromatics with acetylenic dienophiles afforded several nitrogen heterocycles in good to moderate yields by using thermal reaction conditions.These reactions were thought tp proceed through sequential cycloaddition-selenium extrusion pathway.
Hexacarbonylmolybdenum-induced Reaction of Isoxazoles. Cycloaddition of Isoxazoles with Acetylenic Esters and Related Reactions
Kobayashi, Tomoshige,Nitta, Makoto
, p. 152 - 157 (2007/10/02)
In the presence of hexacarbonylmolybdenum, substituted isoxazoles undergo a cycloaddition reaction with dimethyl acetylenedicarboxylate across the C-4-C-5 bond to give 3,4-bis(methoxycarbonyl)pyridine derivatives.In a similar cycloadition of isoxazoles with methyl propiolate, 4-(methoxycarbonyl)pyridine derivatives were also obtained.The β-carbon atom of methyl propiolate could intervene in the bonding with the C-5 position of the isoxazoles regioselectively.A mechanism involving a complexed 2-oxa-3-azabicyclohepta-3,6-diene derivative and the subsequent N-Oand C-1-C-5 bond cleavage leading to a complexed (β-ketovinyl)nitrene intermediate is proposed for the formation of pyridine derivatives.In order to clarify the mechanistic aspect, the reaction of 4-phenyl-2-oxa-3-azabicyclohepta-3,6-diene and its related compounds were also studied to give pyridine derivatives.
