Effect of methoxyl group position on the regioselectivity of ammonia substitution reactions involving 3,3'-dichloro-2,2'-binaphthoquinones.
A series of methoxyl-substituted 3,3'-dichloro-2,2'-binaphthoquinones 2 were prepared and evaluated for regioselectivity in ammonia substitution reactions. Biquinone 2b underwent regiospecific amination at the unsubstituted chloronaphthoquinone unit whereas the isomeric biquinone, 2c, produced moderate regioselectivity (85:15). Biquinone 2d, however, showed no level of regioselectivity demonstrating that the position of the methoxyl group influences the regiochemistry. The intramolecular hydrogen bond in biquinone 5 altered the regioselectivity. Semiempirical calculations revealed comparatively larger LUMO coefficients at the chlorinated carbons that underwent preferential substitution.
Stagliano
Kenneth W
KW
Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, Chicago, IL 60616, USA. stagliano@iit.edu
Lu
Zhenhai
Z
Emadi
Ashkan
A
Harwood
John S
JS
Harwood
Cynthia A
CA
D000641:Ammonia / Q000737:chemistry*; D000998:Antiviral Agents / Q000737:chemistry*; D004583:Electrons; D006860:Hydrogen Bonding; D015394:Molecular Structure; D011809:Quinones / Q000737:chemistry*
D000998:Antiviral Agents; D011809:Quinones; D000641:Ammonia