1246218-89-2Relevant academic research and scientific papers
Stereocontrolled photodimerization with congested 1,8-Bis(4′-anilino) naphthalene templates
Ghosn, Marwan W.,Wolf, Christia'
experimental part, p. 6653 - 6659 (2010/11/05)
Suzuki cross-coupling of a 1,8-dihalonaphthalene with 4-methoxy-3- methylphenylboronic acid or 4-acetamidophenylboronic acid and subsequent functional group transformation gave 1,8-bis(3′-methyl-4′-anilino) naphthalene, 16, and 1,8-bis(4′-anilino)naphthalene, 21, in 65% and 90% overall yield, respectively. These congested compounds exhibit two cofacial aniline rings that favor a proximate, parallel arrangement of covalently attached cinnamoyl units suitable for stereoselective photodimerization. The [2 + 2]cycloaddition was found to proceed with high yield and exclusive formation of cis,trans,cis-cyclobutane-1,2-dicarboxylic acids. Amide formation with cinnamoyl chloride and template 21 followed by photochemical dimerization and acidic hydrolysis gave β-truxinic acid, 10, in 69% overall yield. Coupling of 21 and (E)-3-(3,4-dimethylphenyl)acrylic acid in the presence of EDC, UV irradiation, and cleavage gave cis,trans,cis-3,4-bis(3,4-dimethylphenyl) cyclobutane-1,2-dicarboxylic acid, 26, in 60% yield. In both cases, the template was quantitatively recovered.
