59795-14-1Relevant academic research and scientific papers
Rhenium- and manganese-catalyzed synthesis of aromatic compounds from 1,3-dicarbonyl compounds and alkynes
Kuninobu, Yoichiro,Nishi, Mitsumi,Kawata, Atsushi,Takata, Hisatsugu,Hanatani, Yumi,Salprima Yudha,Iwai, Aya,Takai, Kazuhiko
experimental part, p. 334 - 341 (2010/03/30)
(Chemical Equation Presented) 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 β-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 β-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 rheniumcatalyzed 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. 2009 American Chemical Society.
Rhenium-catalyzed synthesis of multisubstituted aromatic compounds via C-C single-bond cleavage
Kuninobu, Yoichiro,Takata, Hisatsugu,Kawata, Atsushi,Takai, Kazuhiko
supporting information; experimental part, p. 3133 - 3135 (2009/05/07)
(Chemical Equation Presented) A reaction between a β-keto ester and an acetylene in the presence of a rhenium complex, [ReBr(CO)3(thf)] 2, as a catalyst, provided a 2-pyranone derivative in excellent yield via retro-aldol reaction (C-C single bond cleavage). By adding an acetylene-bearing ester group(s) after the formation of 2-pyranones, an aromatization reaction proceeded and multisubstituted aromatic compounds were obtained in good to excellent yields.
