Palladium(II)-Catalyzed Synthesis of 2<i>H</i>,3′<i>H</i>-Spiro[benzofuran-3,2′-naphthoquinones]
作者:Pieter Claes、Jan Jacobs、Bart Kesteleyn、Tuyen Nguyen Van、Norbert De Kimpe
DOI:10.1021/jo400852z
日期:2013.9.6
skeleton, were synthesized starting from 2-aryloxymethyl-1,4-naphthoquinones by means of a palladium(II)-catalyzed reaction, which is a new spirocyclic transformation. Under optimal conditions, i.e. 10 mol % of palladium(II) acetate, 15 mol % of 3,5-dichloropyridine, and 5 mol % of trifluoroacetic acid in acetic acid at 110 °C, various 2H,3′H-spiro[benzofuran-3,2′-naphthoquinones] were synthesized in yields
2 ħ,3' ħ -螺[苯并呋喃-3,2'-萘],构成一个新的螺杂环骨架,合成由2-芳氧基-1,4-萘醌开始通过钯(II) -催化的反应的手段,这是一个新的螺环转变。在最佳条件下,即10摩尔%的钯(II)乙酸盐,3,5-二氯吡啶,并在110℃,5%(摩尔)在乙酸中的三氟乙酸,各种2的15摩尔%ħ,3' ħ -螺[合成了苯并呋喃-3,2'-萘醌],其收率强烈依赖于芳氧基的取代方式。未取代或邻位发现用三氟乙酸处理后,被取代的2-芳氧基甲基-1,4-醌重排成相应的2-(4-羟基芳基)-1,4-醌。