SmI<sub>2</sub>-Promoted Radical Addition Reactions with <i>N</i>-(2-Indolylacyl)oxazolidinones: Synthesis of Bisindole Compounds
作者:Karl B. Lindsay、Francesc Ferrando、Kasper L. Christensen、Jacob Overgaard、Tomàs Roca、M.-Lluïsa Bennasar、Troels Skrydstrup
DOI:10.1021/jo070273d
日期:2007.5.1
major product isolated in yields from 55 to 59% represents an unsymmetrical dimer arising from 1,4-addition to the 2-indolecarboxylic acid derivative of a possible ketyl-type radical anion intermediate originating from the reduction of the exocyclic carbonyl group of the N-acyl oxazolidinone. The minor dimer, represented by a symmetrical diketone, was produced in yields ranging from 11 to 23%. Even in the
在-78°C下用二碘化sa处理吲哚环的取代模式不同的N-苄基2-吲哚羧酸的N-酰基恶唑烷酮导致形成两个吲哚二聚体产物。分离出的主要产物的产率为55-59%,其代表不对称的二聚体,该不对称的二聚体是由于N的外环羰基还原引起的可能的酮基型自由基阴离子中间体的2-4-吲哚羧酸衍生物的加成而产生的。-酰基恶唑烷酮。以对称二酮为代表的次要二聚体的产率为11%至23%。即使存在α,β-不饱和酰胺,二聚化也是优选的途径,而不是γ-酮酰胺的形成。用酸处理后,不对称的吲哚二聚体环化形成二吲哚醌。最后,在两种情况下,吡咯-2-羧酸和3-吲哚羧酸的N-酰基恶唑烷酮优选在SmI 2的存在下与丙烯酰胺进行CC键形成而不是二聚化。