Rhenium- and manganese-catalyzed synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes.
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.
Kuninobu
Yoichiro
Y
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
Nishi
Mitsumi
M
Kawata
Atsushi
A
Takata
Hisatsugu
H
Hanatani
Yumi
Y
Yudha
Salprima S
SS
Iwai
Aya
A
Takai
Kazuhiko
K
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
D000480:Alkynes; D006841:Hydrocarbons, Aromatic; D007659:Ketones; D008345:Manganese; D012211:Rhenium