title: Synthesis of substituted benzenes and phenols by ring-closing olefin metathesis.
abstract: New synthetic approaches to substituted aromatic compounds are reported. Ring-closing olefin metathesis (RCM)/dehydration and RCM/tautomerization are the key processes in the synthesis of substituted benzenes 3 and phenols 6, respectively. Readily accessible 1,5,7-trien-4-ols 7, which are the precursors of benzenes, were prepared from beta-halo-alpha,beta-unsaturated aldehydes 11 or beta-halo-alpha,beta-unsaturated esters 19 by utilizing reliable transformations in which cross-coupling with vinylic metal reagents 12 and allylation with allylic metal reagents 13 were employed as carbon-carbon bond forming reactions. RCM of 7, followed by dehydration, afforded a wide variety of substituted benzenes 3. In addition, RCM of 1,5,7-trien-4-ones 9, which were prepared by oxidation of 7, furnished various substituted phenols 6 by automatic tautomerization.
authors.affiliation: Department of Chemistry, Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan. kyoshida@faculty.chiba-u.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Imamoto
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D001555:Benzene Derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D003681:Dehydration; D015394:Molecular Structure; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D001555:Benzene Derivatives; D010636:Phenols