489423-03-2Relevant academic research and scientific papers
Regioselective C-C bond formation reactions on 2,3-dibromo- and 2,3,5-tribromobenzofuran as an access to multiply substituted benzofurans. Total syntheses of eupomatenoids 3, 4, 5, 6, and 15
Bach, Thorsten,Bartels, Marc
, p. 925 - 939 (2007/10/03)
Regioselective C-C-bond formation reactions at 2,3-dibromobenzofuran (1) and 2,3,5-tribromobenzofuran (6) were studied. Pd-catalyzed Sonogashira and Negishi cross-coupling occurred with perfect regioselectivity at carbon atom C-2 to provide 2-substituted 3-bromobenzofurans (12, 14) and 3,5-dibromobenzofurans (17, 18) in 50-91% yield. A regioselective displacement of the bromine substituents in 3,5-dibromobenzofurans 18 was achieved by a halogen-metal exchange reaction at carbon atom C-3 and by a Nicatalyzed Kumada cross-coupling at C-5. The methodology was applied to the synthesis of eupomatenoids 3, 4, 5, 6, and 15 (5). The synthesis of these compounds was achieved in overall yields of up to 60%.
Synthesis of eupomatenoids by three consecutive transition metal-catalyzed cross-coupling reactions
Bach, Thorsten,Bartels, Marc
, p. 9125 - 9127 (2007/10/03)
Six different eupomatenoids (1a-c, 1f-h) were prepared from 2,3,5-tribromobenzofuran (2) in a concise and high-yielding synthetic sequence. The overall yields vary between 29 and 60% over four to six steps. Key to the success of the syntheses is the high
