Theoretical study of 1,3-dipolar cycloadditions of nitrone and fulminic acid with substituted ethylenes

✍ Scribed by Magnuson, Eric C.; Pranata, Julianto

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 269 KB
• Volume: 19
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/(sici)1096-987x(199812)19:16<1795::aid-jcc1>3.0.co;2-g

✦ Synopsis

Molecular orbital calculations were performed to examine the electronic effects involved in the regioselectivity in the 1,3-dipolar cycloaddition reaction of nitrone and fulminic acid. The substituted ethylene dipolarophiles were selected to represent a range of electron-donatingrwithdrawing abilities: Ž . amino, methyl, carbaldehyde both in the s-cis and the s-trans conformations , and nitrile. The reactions were all asynchronous, with early transition sites. The regioselectivity was correlated with the ability of the substituent to donate or withdraw electrons. With electron-donating substituents, the substituent was directed preferentially to the oxygen end of the dipole and this shifted toward the other regioisomer as the electron-withdrawing ability of the substitutent increased.