作者:Allan R. Pinhas、Matthew T. Hancock
DOI:10.1055/s-2004-831174
日期:——
Reactions of N-alkyl-substituted aziridines with LiI followed by an electrophile are discussed. In the first series of reactions, the electrophile is carbon dioxide and the product is an oxazolidinone. In all cases, either no reaction occurred or a high yield of product was obtained. HMPA had to be added to some reactions to dramatically improve the regiochemistry. Net retention of stereochemistry was observed. In the second series of reactions, the electrophile is an iminium salt and the product is a 1,2-diamine. Here the reaction is highly regioselective in THF without the addition of HMPA. Unlike the oxazolidinone chemistry, the diamine formation works equally well with or without the addition of LiI. With respect to the regiochemistry, the results are the same with and without added LiI. However, with respect to the stereochemistry, in the presence of added LiI, the reaction with the iminium salt goes with net retention of stereochemistry. In contrast, with no added LiI, in some cases the reaction goes with net retention and in some cases with net inversion of stereochemistry.
讨论了 N-烷基取代的氮丙啶与 LiI 以及亲电子体的反应。在第一组反应中,亲电子体是二氧化碳,产物是恶唑烷酮。在所有反应中,要么没有发生反应,要么得到的产物产量很高。有些反应必须加入 HMPA 才能显著改善区域化学性。观察到了立体化学的净保留。在第二系列反应中,亲电子体是亚胺盐,产物是 1,2-二胺。该反应在 THF 中具有高度区域选择性,无需添加 HMPA。与噁唑烷酮化学反应不同的是,无论是否添加 LiI,二胺的生成效果都一样好。在区域化学方面,添加和不添加 LiI 的结果是一样的。不过,在立体化学方面,在添加 LiI 的情况下,与亚胺盐的反应会净保留立体化学。与此相反,在不添加 LiI 的情况下,在某些情况下反应会净保留立体化学,而在某些情况下则会净反转立体化学。