title: Rhenium- and manganese-catalyzed synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes.
abstract: We have succeeded in the development of three approaches to the synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes. The first approach is a manganese-catalyzed [2+2+2] cycloaddition between 1,3-dicarbonyl compounds, which have no substituents at the active methylene moiety, and terminal alkynes. This reaction proceeds with high regioselectivity when aryl acetylenes are employed as the alkyne component. The second approach is a rhenium- or manganese-catalyzed formal [2+1+2+1] cycloaddition between beta-keto esters and two kinds of alkynes. In this reaction, the aromatic compounds are obtained by the following reaction sequence: (1) insertion of the first alkyne into a carbon-carbon single bond of a beta-keto ester, (2) formation of 2-pyranones via intramolecular cyclization with the elimination of ethanol, and (3) Diels-Alder reaction between the formed 2-pyranone and the second alkyne. This reaction provides multisubstituted aromatic compounds in a regioselective manner. The third approach is a rhenium-catalyzed formal [2+2+1+1] cycloaddition reaction from two 1,3-diketones and one alkyne. In this reaction, the aromatic skeleton is constructed from three carbons of the first 1,3-diketone, two carbons of the alkyne, and one carbon of the second 1,3-diketone.
authors.affiliation: Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama 700-8530, Japan. kuninobu@cc.okayama-u.ac.jp
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Kuninobu
authors.forename: Mitsumi
authors.initials: M
authors.lastname: Nishi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawata
authors.forename: Hisatsugu
authors.initials: H
authors.lastname: Takata
authors.forename: Yumi
authors.initials: Y
authors.lastname: Hanatani
authors.forename: Salprima S
authors.initials: SS
authors.lastname: Yudha
authors.forename: Aya
authors.initials: A
authors.lastname: Iwai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Takai
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006841:Hydrocarbons, Aromatic / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D012211:Rhenium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D006841:Hydrocarbons, Aromatic; D007659:Ketones; D008345:Manganese; D012211:Rhenium